Disinfecting methods and compositions

ABSTRACT

A method of disinfecting surfaces said method comprising applying a disinfectant solution to surface to be disinfected and allowing the solvent to evaporate or wiping the excess solution from the surface after a period of time wherein the solution is an antimicrobial metal ion-acid solution.

The present patent application claims the benefit of prior filed U.S. Provisional Patent Application No. 60/930,913, filed May 18, 2007 and entitled “Bioactive Compositions and Use Thereof” which is hereby incorporated herein in its entirety by reference.

FIELD OF THE INVENTION

The present invention relates to novel methods for the disinfecting of various substrates, especially touch surfaces; surfaces in contact with water and air flow; floors, walls and ceilings and the like of medical, research, pharmaceutical, and food storage, preparation and processing facilities; and surfaces of articles and mobile substrates that are easy conveyances for plant, human and animal pathogenic bacteria, fungi, protists, viruses and other microorganisms. Specifically, the method comprises treating said surfaces with a novel antimicrobial metal ion-acidic solution having low levels of bioactive metal ion, alone or, preferably, in further combination with one or more surfactants capable of interacting with cell wall membranes of microorganisms, especially pathogenic microbes.

BACKGROUND OF THE INVENTION

Bioactive materials for killing or inhibiting the growth and/or proliferation/spreading of bacteria, fungi, and other microorganisms have long been sought and employed in society. Their use dates back centuries, if not thousands of years. Early applications had ranged from pharmaceutical or health related applications to disinfectant and purification applications and more. More recent applications include a whole host of uses, with the largest use, by volume, seen in the agricultural industry. Perhaps one of the earliest bioactive materials was metallic silver and, subsequently, silver salts.

While early bioactive agents were most often metals and simple metal salts, modern science and chemical synthesis has enabled the development and production of synthetic agents, most often organic and organometallic agents, for antibacterial, antifungal and other like applications. Indeed, for many applications, especially pharmaceutical applications, the organic agents have, for the most part, eclipsed the use of inorganic bioactive agents. While inorganic and organometallic materials still command a significant market share of the agrichemical business, their use is limited due to their health and safety concerns, especially from an environment perspective.

Despite the great success and huge market share/volume commanded by organic pharmaceutical, antibacterial and agrochemical agents, they have not come without cost and consequences. In all areas of, applications, a marked and growing trend has emerged: namely the manifestation and spreading of a resistance to such organic agents in most all, if not all, microorganisms. While this resistance is neither universal nor complete, it is growing and involves more and more organic agents. Furthermore, as this resistance grows, so too does the apparent virulence of the affected microorganisms as well as their ability to quickly adapt to and manifest resistance to new bioactive agents and combinations thereof. In this respect, we are all well aware of the growing resistance of bacteria, especially pathogenic bacteria, to traditional pharmaceutical agents and disinfectants and the subsequent appearance of what are commonly referred to as superbugs: pathogenic bacteria that show strong resistance to traditional organic antibacterial and pharmaceutical agents. Two particularly disconcerting and exemplary human pathogens that have evolved drug resistance tendencies are MRSA and drug-resistant and, more recently, multi-drug resistant M. tuberculosis. The same trend has been seen in the agrichemical industry where, for example, despite the great fanfare and promise behind the introduction of strobilurin fungicides in the mid-1990s, resistance had been found after just a couple years use in certain applications.

And, whether a direct or indirect consequence of the appearance of superbugs and/or the growing awareness of the ease by which bacteria can spread combined with an increasing concern for potentially pandemic diseases such as SARS and Bird Flu, we have become a population that is more and more pre-occupied with hygiene and general cleanliness. Consequently, there has been a huge proliferation and exponential growth in the widespread and indiscriminate use and application of cleansers and disinfectants that contain organic antimicrobial agents as well as in the production, marketing and use of a whole host of consumer products having one or more antimicrobial agents incorporated therein, all in an effort to ward off exposure to bacteria, particularly pathogenic bacteria. However, this indiscriminate use of organic agents has come with, or at least presents the possibility for, an overall increase in antimicrobial resistant organisms. By eradicating the weaker organisms, the stronger and, most often more damaging, organisms are left.

Such concerns, however, are not limited to our living environment, but also arise with respect to our food and water supply as well. Specifically, while resistance is certainly of great concern, perhaps and even greater concern is the human and environmental toll associated with the widespread use of antimicrobial agents: not just organic antimicrobials and antibiotics, but inorganic, especially metals, as well. For more than half a century now, more and more scientific literature has appeared correlating long-term exposure to (direct and indirect) and use of organic agrichemicals to various diseases and teratogenic, mutanogenic, carcinogenic, and other adverse health consequences in animals and, more importantly, the human population. Similarly, the plethora of organic antibiotics and other pharmaceutical agents in the market have shown in increasing tendency of undesirable and, oftentimes, fatal or near-fatal side-effects or consequences of their long-term use. As recent news reports have indicated, pharmaceutical agents, antimicrobial agents and agrichemical agents all are appearing more and more as unintended components in our food chain and, more importantly, in the drinking water supplies. The latter resulting from many sources including runoff from fields where they are applied, runoff from wastes from pens where livestock are fed and housed, and, as insignificant as it may seem at first, from the mere dumping of expired and unused pharmaceutical agents in the toilet.

Thus, there is an almost overwhelming need and demand for highly effective disinfectants that can be used universally, or nearly so, without concern, or certainly with reduced concern, for environmental contamination and toxicity.

Similarly, there is an almost overwhelming need and demand for disinfectants that will not or are less likely to induce resistance in target organisms.

SUMMARY OF THE INVENTION

In accordance with the present invention there are provided disinfectants useful in disinfecting and/or inhibiting the growth and proliferation of known human, animal and plant pathogens, including molds, said compositions comprising a) an acid solution having a pH of less than 6 whose acid concentration is from about 0.01% to about 10%; b) at least one antimicrobial metal ion source partially, or preferably, fully dissolved or soluble therein, c) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, and, optionally, though preferably, at least one anionic, non-ionic and/or amphoteric surfactant that impacts or interacts with cell wall membranes of microorganisms, especially pathogenic microbes, or the function thereof, which surfactant is the same as or, more typically, different form the wetting surfactant (c), wherein the acid is present in a molar excess relative to the antimicrobial metal ions and the total level of the antimicrobial metal ions in the solution is from about 20 ppm to about 1000 ppm, preferably from about 25 to about 500 ppm, most preferably from about 50 to about 300 ppm. Preferably these compositions will have at least a 2× molar excess, preferably at least a 5× molar excess of the acid relative to the metal ion(s), and a pH of from about 1.5 to about 5, most preferably from about 2 to about 4, and both surfactants or a single surfactant that satisfies both surfactant requirements are present.

According to yet another embodiment of the present invention, there is provided a method of disinfecting and/or inhibiting the growth and proliferation of known human, animal and plant pathogens, including molds, on various surfaces said method comprising the steps of i) applying to said surface a disinfectant comprising a) an aqueous or aqueous-based acid solution; b) at least one antimicrobial metal ion source partially, or preferably, fully dissolved or soluble therein, and c) optionally, though preferably, especially where the acid is other than a mineral acid, A) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, B) at least one anionic, non-ionic and/or amphoteric surfactant that impacts or interacts with cell wall membranes of microorganisms, especially pathogenic microbes, or the function thereof, which surfactant is the same as or, more typically, different from the wetting surfactant (A), or a combination of at least one of said wetting surfactants (A) and at least one of said anionic, non-ionic and/or amphoteric surfactants (B), wherein the disinfectant has a pH of less than 6 and the acid is present in a molar excess relative to the antimicrobial metal ions and wherein the total level of the antimicrobial metal ions in the solution is from about 20 ppm to about 1000 ppm, preferably from about 25 to about 500 ppm, most preferably from about 50 to about 300 ppm and ii) either allowing the solvent of the solution to evaporate so as to leave an antimicrobial presence on the substrate or, preferably after a short period of time, wiping the excess solution from the surface. Preferably the method will employ a disinfectant wherein the acid solution has a concentration of from about 0.01% to about 10% by weight, more preferably from about 0.1% to about 4.0% by weight, and the acid is present in at least a 2× molar excess, preferably at least a 5× molar excess, of the acid relative to the metal ion(s), and at least one of the two surfactant types (A) and (B), most preferably at least one of both types of surfactants (A) and (B) or at least one surfactant that satisfies both surfactant requirements, is present. Additionally, the pH may be from about 1.5 to about 5, preferably from about 2 to about 4, most preferably greater than 2. In essence, while the acidic environment is essential, the acid and/or the acidity should not be so strong as to adversely affect the surface or the appearance of the surface to which the disinfectant is applied.

DETAILED DESCRIPTION

The present invention is centered on the use of an aqueous or aqueous-based disinfectant comprising one or more sources of antimicrobial metal ions, an acid, and, optionally, though preferably, one or more surfactants capable of enhancing the wet-out or wetting of the surface being treated with the disinfectant and/or that is known to impact and/or interact with cell walls or membranes of microorganisms, especially pathogenic microbes. For convenience, the very essence of the disinfectant, namely the acid solution having the antimicrobial metal ion source dissolved therein is henceforth oftentimes referred to as the “bioactive acid solution” wherein the term “bioactive” is intended to include agents that kill or prevent or inhibit the growth and/or proliferation of bacteria, fungi, viruses, and plant, stramenophile and fungi-like protists that are associated with human, animal and plant illnesses or diseases.

The acids that may be used in preparing the disinfectant solutions of the present invention are either solid or liquid in their natural state and are readily soluble or dissolved in or miscible with water or an aqueous based solvent. Exemplary acids include the organic acids, especially the carboxylic acids such as citric acid, valeric acid, itaconic acid, acetic, citriconic acid, lactic acid, malic acid, succinic acid, aldaric acid, malonic acid, proprionic acid, malonic acid, maleic acid, salicylic acid, glutaric acid, tartaric acids, benzoic acid and the like, as well as the mineral acids such as nitric acid, sulfuric acid, phosphoric acid, boric acid, and the like. The preference is for weaker or moderate acids such as aldaric, citric, malic, and lactic acids as opposed to the moderate to strong mineral acids like boric and phosphoric acids. However, strong acids, especially strong mineral acids like sulfuric or nitric acid, may be used; however, depending upon the strength of the acid, it may be preferable to buffer the acid so as to avoid concern with its handling and, more importantly, with respect to adversely affecting the substrate and/or the appearance of the substrate to which it is applied. Thus, while efficacious, it is most preferable to avoid mineral acids and strong acids and, instead, employ carboxylic acids and other weak acids. Additionally, though some suitable acids fall outside of this range, it is desirable that the pKa (in water @ 25° C.) of the acid be greater than 0, preferably greater than 1, most preferably greater than 1.5.

As noted, acidity is critical to the efficacy of the disinfectant solutions of the present invention. Generally speaking, the pH of the disinfectant solutions of the present invention will be less than 6, preferably from about 1.5 to 5 and more preferably from about 2 to about 4, most preferably greater than 2.

The second critical aspect of the acid concentration relates to the excess molar equivalence of acid to the antimicrobial metal ions present in the disinfectant solutions. At a minimum, there must be a 2 times molar excess, though preferably there is at least a 5 times, and most preferably at least a 10 times, molar excess acid. These levels are typically attained by formulating bioactive acid solutions whereby the acid concentration in the final diluted state of the bioactive composition is from about 0.01% to about 10%, preferably from about 0.1% to about 4% by weight of the solution. Higher concentrations may also be used, e.g., up to 20% or more, provided that the substrate to which the disinfectant solution is to be applied is not adversely affected by the higher acid content and/or the acid is a weak or weakly moderate acid.

The second critical component of the disinfectant solutions is the antimicrobial metal ion: more aptly its metal ion source. Suitable metal ions are selected from the group consisting antimicrobial transition metal ions and poor ions that have shown antimicrobial bioefficacy. Preferred metal ions are selected from the group consisting of silver, copper, zinc, mercury, tin, iron, gold, lead, bismuth, cadmium, chromium and thallium ions or combinations of any two or more of the foregoing, more preferably silver, copper, zinc, tin, iron, gold and iron and combinations thereof. Most preferably, the metal ions are selected from the group consisting of silver, copper and zinc ions and combinations of any two or all three. Disinfectant solutions in which at least two and preferably all three of these most preferred ions are present are especially beneficial and preferred. Where multiple antimicrobial metal ions are present, each will be present in a molar amount of 3 to 97 percent, preferably 9 to 91 percent, more preferably 20 to 80 percent. In its preferred embodiment, where multiple metal ions are present, they will be present in an equal amount whereby no one metal ion is more than 20 times, more preferably no more than 10 times that of any other metal ion. Especially good results have been found where each antimicrobial metal ion is present in an equal amount, by weight.

The metal ion is source is added to the acid solution in the form of a source compound, salt or complex that readily releases the ions or otherwise dissociates in the acid solution or as a preformed solution of the metal ion source in water or an aqueous-based solvent. Exemplary salts and organometallic compounds that may suitably serve as the ion sources include the respective oxides, sulfides, carbonates, nitrates, phosphates, dihydrogen phosphates, sulfates, oxalates, quinolinolates, thiosulfates, sulfonates, phthalates, hydroxides, glycolates, and the like of the antimicrobial metals as well as the carboxylic acid salts thereof, especially the simple carboxylates, such as the citrates, benzoates, acetates, lactates, etc. of said antimicrobial metals. Other salts such as the halide salts and substituted halide salts, such as the halides, hexafluoro-antimonates, tetrafluoroborates, and perchlorates of said antimicrobial metals may be used though they are less desirable as they tend to have slow and/or poor solubility, especially in water. Specific metal ion sources include, but are certainly not limited to, silver nitrate, silver oxide, silver acetate, silver citrate, cupric oxide, copper hydroxide, cuprous oxide, copper oxychloride, cupric acetate, copper quinolinolate, copper citrate, zinc oxide, zinc citrate, and the like.

It has also been surprisingly found that certain inorganic complexes may also serve as the metal ion source. Specifically, ion-exchange type antimicrobial agents and dissolving glass antimicrobial agents may be used where the carrier matrix of these materials is soluble in the acid or diluted acid. For example, it has been found that zeolites are readily soluble in concentrated citric acid. Here the metal ion source or sources are added to the acid with mixing until the particles are dissolved. It is also contemplated that these metal ion sources may be only partially dissolved so as to provide for a longer term source of the antimicrobial metal ion. While these ion sources tend to dissolve in the diluted acid, to speed up and/or enhance the dissolving of the metal ion source, it is preferable to dissolve them in a concentrated acid solution, preferably one of from about 40% to 80% concentration.

Suitable ion-exchange type agents include, but are not limited to aluminosilicates, zeolites, hydroxyapatite, and zirconium phosphates, all of which are commercially available and/or fully described in the patent literature. For example, antimicrobial metal ion-containing hydroxyapatite particles are described in, e.g., U.S. Pat. Nos. 5,009,898 and 5,268,174; antimicrobial metal ion-containing zirconium phosphates are described in, e.g., U.S. Pat. Nos. 4,025,608; 4,059,679; 5,296,238; 5,441,717 and 5,405,644 as well as in the Journal of Antibacterial and Antifungal Agents, Vol. 22, No. 10, pp. 595-601, 1994; and antimicrobial metal ion-containing aluminosilicates and zeolites are described in, e.g., U.S. Pat. Nos. 4,911,898; 4,911,899; 4,938,955; 4,938,958; 4,906,464; and 4,775,585, all of the aforementioned patents hereby being incorporated herein by reference in their entirety. Suitable soluble glasses include those described in, e.g., U.S. Pat. No. 5,470,585, which is also incorporated herein by reference in its entirety.

While individual metal ion sources may be used, it is also desirable to use combinations of metal ion sources so as to provide a mixture of metal ions. In certain instances, a single source may provide multiple metal ions. For example, preferred ion-exchange type metal ion sources include AgION AJ10D which contains both silver and zinc ions and AgION AC10D which contains both silver and copper ions. Most preferably, the metal ion sources are the readily soluble salts and compounds, as mentioned above, and most preferably the combination of such compounds whereby solutions having equal or relatively equal concentrations of each of silver, copper and zinc ions are prepared. Suitable combinations include combinations of silver citrate, copper citrate and zinc citrate as well as combinations of silver nitrate, copper sulfate and zinc oxide.

The amount of the antimicrobial metal ion source to be incorporated into the disinfectant is that amount which is sufficient to provide a concentration of from about 20 ppm to about 1000 ppm, preferably from about 25 ppm to about 500 ppm, more preferably about 50 ppm to about 300 ppm, of each antimicrobial metal ion in the disinfectant solution. Of course higher levels could be used but are not necessary to provide suitable bioefficacy and, more importantly, such higher use conflicts with the desired intent of minimizing metal addition to the environment. Thus, in following with said objective, it is preferable to use the minimal, or nearly so, amount possible for the desired application.

Optionally, though preferably, especially where the acid is other than a mineral acid, the disinfectant solution further comprises A) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, and/or B) at least one anionic, non-ionic and/or amphoteric surfactant that impacts or interacts with cell wall membranes of microorganisms, especially pathogenic microbes, or the function thereof, an “impact surfactant.” More preferably, at least one of the two types of surfactants is present, most preferably a combination of both a wetting surfactant and an impact surfactant and/or the at least one surfactants acts a both a wetting surfactant and an impact surfactant. Although good bioefficacy has been achieved in weak and moderate acid bioactive acid solutions without an impact surfactant, the use of an impact surfactant, most preferably a combination of impact surfactants, should be and is generally preferred. Furthermore, while certain strong and very strong acids, especially mineral acids, do not warrant the need for impact surfactants, e.g., phosphoric acid, it is especially desirable, and in some instances necessary, e.g., where other than only short term bioefficacy is desired, to employ one or more impact surfactants.

Suitable surfactants for use in the disinfectant solutions include anionic, cationic, non-ionic and amphoteric (e.g., zwitterionic) surfactants, especially those that are fully or substantially water soluble. Suitable impact surfactants are anionic, non-ionic and/or amphoteric surfactants such as the sulfonates, sulfates, sulfosuccinates, sarcosinates, mono and diglycerides, amine oxides, ether carboxylates, betaines, sulfobetaines, gylcinates and the like, but typically excluding those surfactants, especially non-ionic surfactants, having polyalkylether units, especially polyethylene oxide units, with degrees of polymerization of the alkylene ether unit of greater than about 6. Suitable wetting surfactants include the foregoing, or at least a good percentage thereof, as well as cationic surfactants and those non-ionic surfactants having polyalkylether units, especially polyethylene oxide units, with degrees of polymerization of the alkylene ether unit of greater than about 6. Additional exemplary wetting surfactants include polyacrylic acid salts, lignosulphonic acid salts, phenolsulphonic or naphthalenesulphonic acid salts, polycondensates of ethylene oxide with fatty alcohols or fatty acids or fatty esters or fatty amines, substituted phenols (in particular alkylphenols or arylphenols), ester-salts of sulphosuccinic acid, taurine derivatives (in particular alkyl taurates), phosphoric esters of alcohols or of polycondensates of ethylene oxide with phenols, fatty acid esters with polyols, or sulphate, sulphonate or phosphate functional derivatives of the foregoing compounds as well as a good percentage of the aforementioned impact surfactants.

Generally speaking, each type of surfactant will be present in an amount of from about 0.001% to about 3%, preferably from about 0.01% to about 0.5%, by weight based on the total weight of the disinfectant solution. Notwithstanding the foregoing, it is to be appreciated that the amount of wetting surfactant, especially in cleaning and disinfecting solutions, may be higher, up to 10%, preferably up to 5%. While higher loadings or each or the combined surfactants could be used, it is not necessary to manifest the desired disinfecting properties of the present invention. Similarly, while lower loadings could be used, the manifestation of any synergistic or enhanced performance owing to the impact surfactant is not likely to be seen. Generally, where the surfactant is basic in nature or one that hydrolyzes in water to form a basic solution, the amount should be minimized and/or the amount of acid increased so as to avoid too much neutralization of the bioactive acid solution.

Exemplary anionic surfactants and classes of anionic surfactants suitable for use in the practice of the present invention include: alcohol sulfates; alcohol ether sulfates; alkylaryl ether sulfates; alkylaryl sulfonates such as alkylbenzene sulfonates and alkylnaphthalene sulfonates and salts thereof; alkyl sulfonates; mono- or di-phosphate esters of polyalkoxylated alkyl alcohols or alkylphenols; mono- or di-sulfosuccinate esters of C₁₂ to C₁₅ alkanols or polyalkoxylated C₁₂ to C₁₅ alkanols; alcohol ether carboxylates; phenolic ether carboxylates; polybasic acid esters of ethoxylated polyoxyalkylene glycols consisting of oxybutylene or the residue of tetrahydrofuran; sulfoalkylamides and salts thereof such as N-methyl-N-oleoyltaurate N_(a) salt; polyoxyalkylene alkylphenol carboxylates; polyoxyalkylene alcohol carboxylates alkyl polyglycoside/alkenyl succinic anhydride condensation products; alkyl ester sulfates; naphthalene sulfonates; naphthalene formaldehyde condensates; alkyl sulfonamides; sulfonated aliphatic polyesters; sulfate esters of styrylphenyl alkoxylates; and sulfonate esters of styrylphenyl alkoxylates and their corresponding sodium, potassium, calcium, magnesium, zinc, ammonium, alkylammonium, diethanolammonium, or triethanolammonium salts; salts of ligninsulfonic acid such as the sodium, potassium, magnesium, calcium or ammonium salt; polyarylphenol polyalkoxyether sulfates and polyarylphenol polyalkoxyether phosphates; and sulfated alkyl phenol ethoxylates and phosphated alkyl phenol ethoxylates; sodium lauryl sulfate; sodium laureth sulfate; ammonium lauryl sulfate; ammonium laureth sulfate; sodium methyl cocoyl taurate; sodium lauroyl sarcosinate; sodium cocoyl sarcosinate; potassium coco hydrolyzed collagen; TEA (triethanolamine) lauryl sulfate; TEA (Triethanolamine) laureth sulfate; lauryl or cocoyl sarcosine; disodium oleamide sulfosuccinate; disodium laureth sulfosuccinate; disodium dioctyl sulfosuccinate; N-methyl-N-oleoyltaurate Na salt; tristyrylphenol sulphate; ethoxylated lignin sulfonate; ethoxylated nonylphenol phosphate ester; calcium alkylbenzene sulfonate; ethoxylated tridecylalcohol phosphate ester; dialkyl sulfosuccinates; perfluoro (C₆-C₁₈)alkyl phosphonic acids; perfluoro(C₆-C₁₈)alkyl-phosphinic acids; perfluoro(C₃-C₂₀)alkyl esters of carboxylic acids; alkenyl succinic acid diglucamides; alkenyl succinic acid alkoxylates; sodium dialkyl sulfosuccinates; and alkenyl succinic acid alkylpolyglykosides.

Exemplary amphoteric and cationic surfactants include alkylpolyglycosides; betaines; sulfobetaines; glycinates; alkanol amides of C₈ to C₁₈ fatty acids and C₈ to C₁₈ fatty amine polyalkoxylates; C₁₀ to C₁₈ alkyldimethylbenzylammonium chlorides; coconut alkyldimethylaminoacetic acids; phosphate esters of C₈ to C₁₈ fatty amine polyalkoxylates; alkylpolyglycosides (APG) obtainable from a acid-catalyzed Fischer reaction of starch or glucose syrups with fatty alcohols, in particular C₈ to C₁₈ alcohols, especially the C₈ to C₁₀ and C₁₋₂ to C₁₋₄ alkylpolyglycosides having a degree of polymerization of 1.3 to 1.6, in particular 1.4 or 1.5.

Exemplary non-ionic surfactants and classes of non-ionic surfactants include: polyarylphenol polyethoxy ethers; polyalkylphenol polyethoxy ethers; polyglycol ether derivatives of saturated fatty acids; polyglycol ether derivatives of unsaturated fatty acids; polyglycol ether derivatives of aliphatic alcohols; polyglycol ether derivatives of cycloaliphatic alcohols; fatty acid esters of polyoxyethylene sorbitan; alkoxylated vegetable oils; alkoxylated acetylenic diols; polyalkoxylated alkylphenols; fatty acid alkoxylates; sorbitan alkoxylates; sorbitol esters; C₈ to C₂₂ alkyl or alkenyl polyglycosides; polyalkoxy styrylaryl ethers; alkylamine oxides; block copolymer ethers; polyalkoxylated fatty glyceride; polyalkylene glycol ethers; linear aliphatic or aromatic polyesters; organo silicones; polyaryl phenols; sorbitol ester alkoxylates; and mono- and diesters of ethylene glycol and mixtures thereto; ethoxylated tristyrylphenol; ethoxylated fatty, alcohol; ethoxylated lauryl alcohol; ethoxylated castor oil; and ethoxylated nonylphenol; alkoxylated alcohols, amines or acids, mixtures thereof as well as mixtures thereof with diluents and solid carriers, in particular clathrates thereof with urea. The alkoxylated alcohols, amines or acids are preferably based on alkoxy units having 2 carbon atoms, thus being a mixed ethoxylate, or 2 and 3 carbon atoms, thus being a mixed ethoxylate/propoxylated, and having at least 5 alkoxy moieties, suitably from 5 to 25 alkoxy moieties, preferably 5 to 20, in particular 5 to 15, in the alkoxy chain. The aliphatic moieties of the amine or acid alkoxylated may be straight chained or branched of 9 to 24, preferably 12 to 20, carbon atoms. The alcohol moiety of the alcohol alkoxylates is as a rule derived from a C₉-C₁₈ aliphatic alcohol, which may be non-branched or branched, especially monobranched. Preferred alcohols are typically 50% by weight straight-chained and 50% by weight branched alcohols.

As noted above, the aforementioned surfactants may be used alone or in combination. Furthermore, while not all of the surfactants mentioned above will provide the desired synergy of the impact surfactants or the enhanced wet-out of the wetting surfactants, they may nevertheless be used in combination with the aforementioned surfactants for their intended function. For example, certain of the aforementioned surfactants may enhance the dissolution or solubility of the metal ion source or acid in the solvent or the dissolution or dispersion of other additives that may be present in the bioactive acid solution. All of these surfactant materials are well known, particularly as components of conventional disinfecting and cleaning compositions, and commercially available.

In the event that any particular surfactant should adversely affect the bioefficacy of the disinfectant solution, that surfactant should be avoided or its use minimized as much as possible. To counteract any such adverse impact, it may be further desired to use, if not already present, or increase the amount of the impact surfactant and/or increase the acid and/or antimicrobial metal ion content. The addition of acid is, an especially suitable option where the surfactant is basic and will neutralize the acid of the bioactive acid solution to a point where the pH no longer less than 6, or whatever lesser pH is desired.

The disinfectant solutions of the present invention may further include one or more conventional bioactive agent for the intended targeted microorganism. For example, in agriculture, one may desire to add a fungicide or fungicide active to a disinfectant solution to be used in disinfecting farm equipment and implements in order to disinfect the farm equipment and implements so as to prevent cross-contamination of plant pathogens from a diseased field to a non-diseased field or, following application of a fungicide or the like to a diseased field, from re-contaminating the treated field by re-introducing a piece of equipment or implement that had been used in the field prior to the treatment. Indeed, as discussed and claimed in co-pending and co-filed International PCT patent application No. US/PCT2008/06358 and corresponding U.S. patent application Ser. Nos. 12/154,130,12/154,132, and 12/154,127, all entitled “Bioactive Agrichemical Compositions and Use Thereof” all of which are hereby incorporated herein by reference in their entirety, such the combination of the bioactive acid solutions of the present invention and the conventional bioactive agents oftentimes provide a marked and unexpected synergy. Hence, that synergy can only enhance the effectiveness of the disinfectant compositions and methods of the present invention. Exemplary synergistic plant pathogenic actives include the amide, acyl amino acid, anilide, benzanilide, furanilide, sulfonanilide, bezamide, furamide, phenyl sulfamide, sulfonamide, valinamide, antibiotic, strobilurin, chloroneb, chlorothalonil, dichlorobenil, dichloran, PCNB, benzimidazole, benzothiazole, bridged diphenyl, carbamate, benzimidazoylcarbamate, carbanilate, conazole, imidazole, triazole, copper, dicarboximide, dichlorophenyl dicarboximide, phthalimide, dinitrophenol, dithiocarbamate, cyclic dithiocarbamate, polymeric dithiocarbamate, imidazole, inorganic mercuric, organomercury, morpholine, organophosphorus, organotin, oxathiin, oxazole, polysulfide, pyrazole, pyridine, pyrimidine, pyrrole, quinoline, quinone, quinoxaline, thiazole, thiocarbamate, thiophene, triazine, triazole, urea, or borate fungicides, especially the strobilurin, dithicarbamate, and triazole fungicides. Of course, this aspect of the present invention is not limited to fungicides and other bioactive actives can be used, and most likely synergistically, with the bioactive acid solutions in the instant.

Alternatively, or in addition to the other bioactive agent, the disinfectant solutions according to the present invention may also include one or more compatible components or additives, preferably additives that are fully or substantially water-soluble, typical of disinfectants and cleaning solutions, including cleaning agents themselves. For example, as mentioned above, there may be additional surfactants that are not wetting surfactants or impact surfactants. Other additives include, but are not limited to thickeners, thixotropic agents, penetrating agents, stabilizers, antifreeze agents, defoaming agents, foaming agents, corrosion inhibitors, dyes, or the like.

The specific additive or combination of additives, the amount thereof, etc. to be employed in the disinfectant solutions of the present invention depends, in part, upon the targeted microorganism, if there is a specific targeted microorganism; the surface or substrate to be treated, e.g., thickeners and/or thixotropes, may be especially desirable for use in disinfectants to be applied to walls and ceilings or to articles having vertical surfaces where there is concern for premature runoff; the nature and environment in which the surface or article to be treated is located or used, e.g., medical devices in a hospital versus implements in a rendering plant or an examination table in physician's office versus a food processing surface, etc. The amount of each added ingredient or additive will be consistent with its conventional use.

As noted above, it is especially desirable to thicken the disinfectant solutions where there is concern that the composition will quickly run off or run down the substrate or surface to which it is applied, particularly where it is desired and intended that the disinfectant be allowed to stand on the surface or substrate for any length of time following application. Suitable thickeners include water-soluble polymers which exhibit pseudoplastic and/or thixotropic properties in an aqueous medium such as gum arabic, gum karaya, gum tragacanth, guar gum, locust bean gum, xanthan gum, carrageenan, alginate salt, casein, dextran, pectin, agar, 2-hydroxyethyl starch, 2-aminoethyl starch, 2-hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose salt, cellulose sulfate salt, polyacrylamide, alkali metal salts of the maleic anhydride copolymers, alkali metal salts of poly(meth)acrylate, and the like. As suitable thickening fillers, including thixotropes, there may also be mentioned attapulgite-type clay, silica, fumed silica, carrageenan, croscarmellose sodium, furcelleran, glycerol, hydroxypropyl methylcellulose, polystyrene, vinylpyrrolidone/styrene block copolymer, hydroxypropyl cellulose, hydroxypropyl guar gum, and sodium carboxymethylcellulose.

In the case of disinfectants that are or may be subject to freezing during storage or use, it is desirable to add antifreeze additives. Specific examples of suitable antifreezes include ethanol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,4-pentanediol, 3-methyl-1,5-pentanediol, 2,3-dimethyl-2,3-butanediol, trimethylol propane, mannitol, sorbitol, glycerol, pentaerythritol, 1,4-cyclohexanedimethanol, xylenol, bisphenols such as bisphenol A or the like. In addition, ether alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, polyoxyethylene or polyoxypropylene glycols of molecular weight up to about 4000, diethylene glycol monomethylether, diethylene glycol monoethylether, triethylene glycol monomethylether, butoxyethanol, butylene glycol monobutylether, dipentaerythritol, tripentaerythritol, tetrapentaerythritol, diglycerol, triglycerol, tetraglycerol, pentaglycerol, hexaglycerol, heptaglycerol, octaglycerol and the like. As a particular subset of suitable antifreeze materials there can be mentioned ethanol, ethylene glycol, propylene glycol and glycerin.

The disinfectant solutions may also contain dyes such as inorganic pigments, such as, for example: iron oxides, titanium oxides, Prussian blue; organic dyestuffs, such as those of the alizarin, azo or metal phthalocyanin type; or of trace elements such as iron, manganese, boron, copper, cobalt, molybdenum or zinc salts. The use of such dyes enables one to determine which areas and substrates have been treated with the bioactive composition. Such marking is especially important for medical, biotechnology and research facilities, especially those employing or having exposure to human pathogens, where one must be certain that all areas, surfaces, articles, etc. that has been or was possibly exposed to a human pathogen, has been treated with the disinfectant. Preferably, the dye is one that is easily washed off so that it may be removed once the disinfecting is completed.

Those skilled in the art, particularly in the cleaning and disinfecting art, will certainly appreciate and immediately identify cleaning agents and other additives and ingredients that would or should be used for their application.

As noted above, it is important to avoid the use of conventional bioactive actives, surfactants, additives, and the like, that interfere with or adversely affect the bioefficacy of the compositions according to the present invention. Most especially, it is important to avoid the use of materials or compounds that are known to or will likely irreversibly or strongly sequester, bind, or complex with the antimicrobial metal ions in solution. In following, not intending to be bound by theory, it is believed that retention of the antimicrobial metal ionic charge is important for maintaining bioefficacy. For example, it is best to avoid the use of ammonium salts such as ammonium sulphate, ammonium chloride, ammonium citrate, ammonium phosphate. To the extent any such materials are present or to be used, their use or, more accurately, the amount thereof, should be minimized and/or the metal ion concentration increased to offset the loss of free ions in solution compounds.

The disinfectant solutions of the present invention may be made by any known method for formulating disinfectant compositions. For example, concentrated stock solutions of each component, or a combination of any two or more components, may be prepared and then the stock solutions combined in appropriate proportion and the blend let down with additional solvent to the final concentration. Alternatively, one may sequentially dissolve each component in the same solvent/solution. Here one would first dissolve that component which either enhances or has the least negative effect on solubility of the remaining components to be added. Yet another alternative is to prepare a pre-mix of any two or more or all of the components and add that to the solvent.

To some extent, the sequence of addition of the components to the solvent and/or the solutions and/or whether a pre-concentrate of one or more components is formed depends upon the solubility of the solids themselves. Where solubility is better or faster in the neat solvent, then each or those components are individually dissolved in the solvent. On the other hand, where the solubility, or the rate thereof, of any one or more of the components of the disinfectant composition is enhanced by, for example, a more acidic solvent, a concentrated solution of the acid if first prepared and then the component or components are sequentially or simultaneously added and dissolve in the concentrated acid solution. This method is especially beneficial for those antimicrobial metal ion sources, like the above-mentioned ion-exchange type antimicrobial metal ion sources, that are readily and best dissolved in an acid solution.

In those instances where solubility of one component is enhance by the concentrated acid solution but another is not, one may simply make the concentrated acid solution, dissolve the favorably soluble component and then dilute the solution before adding the final component. Similarly, as necessary or appropriate, the solvent/solutions may be heated and are preferably agitated to enhance the solubility/expedite the dissolving of the solids in the liquid system. Furthermore, while the dissolution of antimicrobial metal ion source or sources is perhaps the simplest and most cost effective method of the preparation of the bioactive acid solutions, these bioactive acid solutions may also be prepared by, e.g., electrolytically generating the metal ion in acid solutions as seen in Arata et. al. (U.S. Pat. No. 6,197,814; US 2003/0198689A1, US 2003/0178374A1; US2005/0245605A1 and US2006/0115440A1, all of which are incorporated herein by reference in their entirety) or by high temperature and pressure as seen in Cummins et. al. (U.S. Pat. No. 7,192,618, incorporated herein be reference).

Surprisingly, the disinfectant solutions show a marked bioefficacy even at the extremely low levels of antimicrobial metal ions as claimed. This is especially desirable as it greatly reduces the amount of metals released to the environment. This benefit has taken on new significance in light of recent water purity investigations showing detectable levels of various pharmaceutical agents in drinking water supplies presumably resulting from the indiscriminate disposal of expired prescriptions by consumers down their drains. Certainly, the use of environmentally toxic antimicrobial agents, including organic biocides as well as heavy metals, must be factored in as a contributor to their own presence in water supplies as well. Thus, the present invention, while not eliminating in total such concerns relative to the antimicrobial metals, greatly reduces the same. Furthermore, the reliance upon antimicrobial metals, as opposed to traditional organic antimicrobial agents, further ensures against or lessens the likelihood of the manifestation of bio-resistance in the targeted organisms: a growing happenstance with organic agents, which, while bothersome at the present time, could lead to catastrophic results if unchecked.

The rate of application of the disinfectant solutions is the same as for conventional disinfectants. Generally speaking, the amount to be applied will be that amount necessary to fully coat or wet the substrate to be treated. Application may be by way of spraying, brushing, coatings, wiping, etc. the disinfectant solution on the surface or substrate to be disinfected. Alternatively, especially in the case of articles, the articles may be dipped in a bath of the disinfectant solution. Additionally, especially where there is concern for airborne pathogens and disinfecting air flow pathways, it is possible to apply the disinfectant as an aerosol to the atmosphere of, preferably, a controlled or enclosed environment or to the air flow, respectively.

The disinfectant solutions may be employed to kill or inhibit the growth and proliferation of known human, animal and plant pathogens. In particular, these solutions are suitable as bioactive agents in combating, including molds. They may be used to disinfect any surfaces and substrates on which the pathogen is or is likely or may be present. They may be applied to the floors, walls, ceilings, doors, windows, etc. of buildings; to any plumbing devices, apparatus and systems including drains, faucets and related elements, water taps; to any waste steam pathways and components, especially in rendering and food processing facilities and plants; to the airflow pathway elements of any air conditioning or air flow system, apparatus, or equipment; to any work surfaces, especially examination tables, food processing counters or tables, and the like; to any touch surfaces including door knobs, light switches, flush levers, telephones, appliance handles, remote controls, etc.; tools, equipment, apparatus, and implements associated with the personal care, medical, dental, mortuary, veterinarian, pharmaceutical, research and development, agricultural, biotechnological, food processing, brewing, meat packing, etc. industries; storage vessels, containers, tankers, ships, aircraft, trains, trucks, cars, tractors, etc., used in any industry where microorganism contamination and/or cross-contamination is of concern; etc.

Quantification or definition of bioefficacy of the disinfectant solutions is not absolute and will vary depending upon when, how and why the disinfectant is used. For example, in the agricultural environment, a disinfecting method that ultimately results in improved yields and/or reduced incidence of or degree of severity of plant diseases is acceptable and, hence efficacious. Similarly, in the food handling and processing industry, a disinfectant method that results in delayed onset of spoilage or the manifestation of aging of a food, especially in fruits and vegetables is of economic benefit and is hence, efficacious. On the other hand, where the concern is human and animal pathogens, most especially human pathogens, efficacy has a much higher standard and typically is wanting of a killing of the target organism on a log scale, typically at least a 95% kill rate, preferably at least a 99%, more preferably a 99.9% kill rate, within a specified period of time. On the other hand, were the pathogen is non-life threatening or of minor concern, as with molds in buildings, a lesser kill rate, while not desirable, is nevertheless efficacious.

As noted above, in certain situations, particularly where human and animal, especially human pathogens, are of concern, bioefficacy typically has a second parameter, time. Specifically, one would typically expect to see the above-mentioned kill rates or bioefficacy within a relatively short period of time, especially where the disinfectant is to be removed, in whole or in part. Generally, one would expect the disinfectant to achieve its intended the kill rate within a half-hour or so, preferably within fifteen minutes, most preferably within a few minutes or less. In following, it is typically expected that the disinfectant will be allowed to stand on the substrate or surface treated for at least fifteen minutes or so, perhaps as short as five minutes: though shorter time periods are envisioned; though one may sacrifice the degree of bioefficacy attained.

On the other hand, kill rates or times are not so important or certainly of less importance with non-human pathogens, especially in the case of plant pathogens. Furthermore, time to achieve the desired kill is not important where it is intended that the disinfectant, or a portion thereof, be left on the substrate. Certainly, though, one would want to see a detectable kill rate or inhibition within a few hours, preferably within an hour or so and that such effect or a substantial portion of the effect remain for some period of time, especially where the disinfectant remains in place.

The following examples are presented as demonstrating the bioefficacy of the disinfectant solutions according to the present invention as well as the unexpected synergy resulting from the use of certain surfactants and/or other conventional bioactive actives and formulated actives. These examples are merely illustrative of the invention and are not to be deemed limiting thereof. Those skilled in the art will recognize many variations that are within the spirit of the invention and scope of the claims.

Saccharomycetes Cerevisiae Studies

A series of experiments (Examples 1-269 below) were conducted to evaluate the performance of the individual components of the claimed bioactive compositions as well as various combinations thereof, including, the claimed compositions themselves, in suppressing the growth of Saccharomycetes Cerevisiae (Fleishmann's Bakers yeast). Saccharomycetes Cerevisiae was selected as a test organism as it is generally accepted in the industry as an indicator or surrogate organism for a wide variety of molds and fungi. In each of these experiments, the same general procedure was followed unless otherwise indicated.

Experimental Detail: A growth medium was prepared by adding 10 grams of nutrient medium (Difco Sabouraud dextrose broth from BD of Franklin Lakes, N.J., USA) to 300 ml of distilled water. Fleishmann's Bakers yeast was then added to the growth medium while mixing using a magnetic stirrer until a uniform dispersion was obtained having an initial turbidity of between about 50 and 100 NTU as measured using a HF Instruments DRT 100B Turbidity Meter. Once the appropriate dispersion was obtained, 20 ml aliquots were then dispensed, with continued mixing, into 40 ml borosilicate glass vials with Teflon lined caps (VWR International Cat. No. 15900-004). The system/component to be evaluated was then added to the vial and intimately shaken to ensure a good, substantially homogeneous mixture. The turbidity of each mixture was then determined and the vial transferred to an incubator at 30° C. Each vial was periodically removed from the incubator and the mixture in the vials assessed for turbidity: the specific timing for such evaluation was as set forth in the discussion of the experiments and the accompanying tables.

In each experiment, unless otherwise specified, a 2 ml aqueous solution containing the specified bioactive system or component thereof was added to the ml yeast suspension and mixed thoroughly. Typically the surfactants were added separately in a concentrated solution in water; however, the volume added was negligible: a fraction of an ml. For convenience in understanding efficacy levels, the amounts or concentrations of the various components presented in each of the following tables and experiments are of the diluted material in the test vial: not of the concentrate added to the test vial. Furthermore, the concentrations presented are on the basis of a 20 ml total volume, not the actual 22+ml volume. Multiplying each of the listed concentrations by 0.9 (or 0.95 with those compositions using 1 ml aqueous solutions) will provide a more accurate assessment of the concentrations of the various components evaluated, i.e., a 5 ppm silver concentration is actually closer to 4.5 ppm. Finally, for those vials to which no bioactive system or component thereof was added (the controls) or which only contained the surfactants, 2 ml of additional growth medium were added to ensure relative equivalent dilutions of the yeast.

In the tables below, the results are presented as the actual turbidity readings (NTU) with a sub-table presenting the change or delta in NTU values. Given the nature of the system, changes in turbidity are reflective of the relative performance/bioefficacy of the bioactive systems and their components. In certain instances, a high level of bioactive material, especially the metal component, caused an immediate and relatively sharp increase in optical density or turbidity. This was believed to have been a result of lysing of at least a portion on the yeast cells themselves. Consequently, especially in those examples having a high level of bioactive, it is equally, if not more, important to look at the change in turbidity from either the half hour or one hour turbidity results, if presented, forward, not from time zero.

EXAMPLES 1-21 Acid Concentration

A first series of experiments was conducted for evaluating the performance of various antimicrobial metals and combinations of such metals, with and without citric acid and with and without sodium lauroyl sarcosinate anionic surfactant. Each of the metals was added in the form of an aqueous solution of their citrate salts, namely, silver citrate, copper citrate and zinc citrate, or, in the case of Examples 16-19, as a mixture of all three citrate salts (MI1). The specific formulations evaluated and the resultant yeast growth study results are shown in Tables 1 and 1A.

TABLE 1 Metal Ion and Citric Na Lauroyl Turbidity (NTU) Amount Acid Sarcosinate Time Time T 18 T 24 T 96 Example (ppm) (wt %) (wt %) zero 1 Hr hours hours Hours 1 Ag 5 ppm 0 44.5 59.6 890 932 995 2 Ag 5 ppm 1 47.5 64 882 902 1044 3 Ag 5 ppm 2 50.9 68.4 881 950 1025 4 Ag 5 ppm 0 0.005 46.8 51.5 596 677 673 5 Ag 5 ppm 1 0.005 59.4 68.4 85 130 854 6 Ag 5 ppm 2 0.005 70.9 75 85 120 880 7 Zn 5 ppm 0 43.8 64.5 992 993 1051 8 Zn 5 ppm 1 46.6 66.5 934 962 1027 9 Zn 5 ppm 2 49.5 71 936 1038 1063 10 Zn 5 ppm 0 0.005 45.9 63 656 747 712 11 Zn 5 ppm 1 0.005 57 71 160 223 744 12 Zn 5 ppm 2 0.005 73 76.5 105 119 466 13 Cu 5 ppm 0 45.6 68 940 1021 1100 14 Cu 5 ppm 1 49 72 940 1018 1102 15 Cu 5 ppm 2 49 74 900 973 1100 16 MI1 0 0.005 39 44.5 449 575 658 17 MI1 1 0.005 73.9 87 100 105 732 18 MI1 2 0.005 132 137 137 137 690 19 MI1 1 0.01 74.5 74.8 87 89 116 20 Control 53.2 69.4 1031 1085 1122 (No Biocide) 21 Control 53.2 78 1101 1093 1128 (No Biocide) * MI1 a 4% citric acid solution containing of 50 ppm each of Ag, Cu and Zn per ml giving ~5 ppm of each in the test vial

TABLE 1A Metal Ion Change in Turbidity from T₀ and Citric Na Lauroyl (delta NTU) Amount Acid Sarcosinate Time T 18 T 24 Example (ppm) (wt %) (wt %) 1 Hr hours hours T 96 Hours 1 Ag 5 ppm 0 15.1 845.5 887.5 950.5 2 Ag 5 ppm 1 16.5 834.5 854.5 996.5 3 Ag 5 ppm 2 17.5 830.1 899.1 974.1 4 Ag 5 ppm 0 0.005 4.7 549.2 630.2 626.2 5 Ag 5 ppm 1 0.005 9 25.6 70.6 794.6 6 Ag 5 ppm 2 0.005 4.1 14.1 49.1 809.1 7 Zn 5 ppm 0 20.7 948.2 949.2 1007.2 8 Zn 5 ppm 1 19.9 887.4 915.4 980.4 9 Zn 5 ppm 2 21.5 886.5 988.5 1013.5 10 Zn 5 ppm 0 0.005 17.1 610.1 701.1 666.1 11 Zn 5 ppm 1 0.005 14 103 166 687 12 Zn 5 ppm 2 0.005 3.5 32 46 393 13 Cu 5 ppm 0 22.4 894.4 975.4 1054.4 14 Cu 5 ppm 1 23 891 969 1053 15 Cu 5 ppm 2 25 851 924 1051 16 MI1 0 0.005 5.5 410 536 619 17 MI1 1 0.005 13.1 26.1 31.1 658.1 18 MI1 2 0.005 5 5 5 558 19 MI1 1 0.01 0.3 12.5 14.5 41.5 20 Control 16.2 977.8 1031.8 1068.8 (No Biocide) 21 Control 24.8 1047.8 1039.8 1074.8 (No Biocide) * MI1 a 4% citric acid solution containing of 50 ppm each of Ag, Cu and Zn per ml giving ~5 ppm of each in the test vial

As seen in Tables 1 and 1A, those formulations having both the acid and the anionic surfactant provided marked yeast growth inhibition through at least the first 24 hour period, even with the low lever of anionic surfactant. Those samples with just the metal ion or the metal ion in combination with the acid had no appreciable effect on yeast growth. Although some inhibition was also noted in those samples wherein only the metal(s) and surfactant were present, the inhibition was not appreciable. Rather, as noted, the further presence of excess acid gave a marked and unexpected level of improvement. Finally, that formulation having all three antimicrobial metal ions, plus the acid and surfactant provided continued to show excellent yeast growth inhibition even at the 96 hour test limit.

EXAMPLES 22-42 Surfactant Evaluation

A similar series of experiments was conducted again to evaluate the performance of various combinations of the components of the bioactive compositions of the present invention as well as to demonstrate other anionic surfactants and combinations of surfactants. The specific formulations evaluated and the yeast growth results are presented in Tables 2 and 2A.

Once again, the importance of all three constituents was evident from the results shown in Tables 2 and 2A. These results further confirm that even a low excess acid content, here 0.4%, provides excellent inhibition in yeast growth through 96 hours. The somewhat less than ideal results shown in Examples 26 and 29 suggest some variation amongst anionic surfactants, at least with sodium lauryl sulfate (SLS), with zinc and copper ions. However, the results are still significantly better than without a surfactant at all and suggest a possible synergy with two. Furthermore, because of the easier solubility of the SLS, as compared to the sodium lauroyl sarcosinate (NaLS), the presence of the SLS helps improve and/or enhance the solubility of the NaLS under acid conditions.

EXAMPLES 43-57 Low Concentration Evaluation

A series of experiments were conducted again to evaluate the performance of various combinations of the components of the bioactive compositions of the present invention, this time focusing on the impact of the low concentrations of the components and their combinations. In this set of experiments, 1 ml aqueous solutions of the bioactive/citric acid components were added to the 20 ml vials. The specific formulations evaluated and the yeast growth results are presented in Tables 3 and 3A.

As seen in Tables 3 and 3A, once again the combination of bioactive metal ions, citric acid and anionic surfactant demonstrated a marked inhibition in yeast growth as compared to the individual components, even at the low concentrations of excess acid and surfactant. Though, once again, the surfactants appeared to have a marginal inhibitory effect, as compared to the controls, on their own, the inhibition was negligible as compared to that of the systems according to the present invention.

TABLE 2 Turbidity (NTU) T 24 Example Metal citrates (ppm) in .4% citric acid Surfactant* (wt %) Time zero T 1 hour T 18 hours hours T 96 Hrs 22 Copper 5 ppm 103 114 410 463 588 23 Zinc 5 ppm 103 118 475 488 589 24 Silver 5 ppm 155 168 181 190 670 25 Copper 5 ppm .005 NaLS 145 146 157 160 149 26 Copper 5 ppm .005 SLS 119 128 252 326 502 27 Copper 5 ppm .005 NaLS:.005 SLS 145 144 156 154 157 28 Zinc 5 ppm .005 NaLS 148 156 157 157 157 29 Zinc 5 ppm .005 SLS 126 134 217 234 539 30 Zinc 5 ppm .005 NaLS:.005 SLS 155 155 157 157 158 31 Silver 5 ppm .005 NaLS 170 170 184 184 180 32 Silver 5 ppm .005 SLS 177 177 193 196 196 33 Silver 5 ppm .005 NaLS:.005 SLS 193 190 198 199 199 34 Copper 2.5 ppm:Zinc 2.5 ppm 99 109 498 510 614 35 Copper 2.5 ppm:Silver 2.5 ppm 128 152 424 530 727 36 Zinc 2.5 ppm:Silver 2.5 ppm 128 151 541 621 720 37 Control I (no biocide) 91 114 560 580 754 38 Control 2 (no biocide) 91 114 563 584 726 39 Copper 2.5 ppm:Zinc 2.5 ppm .005 NaLS:.005 SLS 192 180 193 193 193 40 Copper 2.5 ppm:Silver 2.5 ppm .005 NaLS:.005 SLS 181 204 205 206 206 41 Zinc 2.5 ppm:Silver 2.5 ppm .005 NaLS:.005 SLS 194 193 212 212 212 42 Copper 2.5 ppm:Silver 2.5 ppm:Zinc 2.5 ppm .005 NaLS:.005 SLS 193 193 199 200 205 *NaLS—sodium lauroyl sarcosinate, SLS—sodium lauryl sulfate

TABLE 2A Change in Turbidity from T0 (delta NTU) Example Metal citrates (ppm) in .4% citric acid Surfactant* (wt %) T 1 hour T 18 hours T 24 hours T 96 Hrs 22 Copper 5 ppm 11 307 360 485 23 Zinc 5 ppm 15 372 385 486 24 Silver 5 ppm 13 26 35 515 25 Copper 5 ppm .005 NaLS 1 12 15 4 26 Copper 5 ppm .005 SLS 9 133 207 383 27 Copper 5 ppm .005 NaLS:.005 SLS −1 11 9 12 28 Zinc 5 ppm .005 NaLS 8 9 9 9 29 Zinc 5 ppm .005 SLS 8 91 108 413 30 Zinc 5 ppm .005 NaLS:.005 SLS 0 2 2 3 31 Silver 5 ppm .005 NaLS 0 14 14 10 32 Silver 5 ppm .005 SLS 0 16 19 19 33 Silver 5 ppm .005 NaLS:.005 SLS −3 5 6 6 34 Copper 2.5 ppm:Zinc 2.5 ppm 10 399 411 515 35 Copper 2.5 ppm:Silver 2.5 ppm 24 296 402 599 36 Zinc 2.5 ppm:Silver 2.5 ppm 23 413 493 592 37 Control I (no biocide) 23 469 489 663 38 Control 2 (no biocide) 23 472 493 635 39 Copper 2.5 ppm:Zinc 2.5 ppm .005 NaLS:.005 SLS −12 1 1 1 40 Copper 2.5 ppm:Silver 2.5 ppm .005 NaLS:.005 SLS 23 24 25 25 41 Zinc 2.5 ppm:Silver 2.5 ppm .005 NaLS:.005 SLS −1 18 18 18 42 Copper 2.5 ppm:Silver 2.5 ppm:Zinc 2.5 ppm .005 NaLS:.005 SLS 0 6 7 12

TABLE 3 Citric Turbidity (NTU) Example Bioactive Metal* Acid (wt %) Surfactant** (wt %) OD (T0) OD (T1 hr) OD (T18) OD (T24) OD (T48) 43 0.01 NaLS 43 45 550 613 521 44 0.02 NaLS 43 40 460 524 624 45 0.01 SLS 43 47 675 728 758 46 0.02 SLS 37 42 495 610 605 47 0.01 NaLS/0.01 SLS 40 41 370 466 580 48 0.005 NaLS/0.005 SLS 43 47 630 696 726 49 0.05 42 46 835 920 878 50 0.1 38 44 780 864 852 51 MI1 0.2 50 62 809 891 915 52 MI1 0.2 0.01 NaLS 64 63 67 68 69 53 MI1 0.2 0.01 SLS 61 65 300 569 1039 54 MI1 0.2 0.005 NaLS/0.005 SLS 60 63 62 63 73 55 MI1 0.2 0.01 NaLS/0.01 SLS 85 76 76 79 79 56 Control 1 43 51 960 997 939 57 Control 2 43 51 890 986 887 *MI1 a 4% citric acid solution containing of 50 ppm each of Ag, Cu and Zn per ml giving (@ 1 ml) ~5 ppm of each in the test vial **NaLS—sodium lauroyl sarcosinate, SLS—sodium lauryl sulfate

TABLE 3A Change in Turbidity from T0 (delta NTU) Example Bioactive Metal* Citric Acid (wt %) Surfactant** (wt %) OD (T1 hr) OD (T18) OD (T24) OD (T48) 43 0.01 NaLS 2 507 570 478 44 0.02 NaLS −3 417 481 581 45 0.01 SLS 4 632 685 715 46 0.02 SLS 5 458 573 568 47 0.01 NaLS/0.01 SLS 1 330 426 540 48 0.005 NaLS/0.005 SLS 4 587 653 683 49 0.05 4 793 878 836 50 0.1 6 742 826 814 51 MI1 0.2 12 759 841 865 52 MI1 0.2 0.01 NaLS −1 3 4 5 53 MI1 0.2 0.01 SLS 4 239 508 978 54 MI1 0.2 0.005 NaLS/0.005 SLS 3 2 3 13 55 MI1 0.2 0.01 NaLS/0.01 SLS −9 −9 −6 −6 56 Control 1 8 917 954 896 57 Control 2 8 847 943 844 *MI1 a 4% citric acid solution containing of 50 ppm each of Ag, Cu and Zn per ml giving (@ 1 ml) ~5 ppm of each in the test vial **NaLS—sodium lauroyl sarcosinate, SLS—sodium lauryl sulfate

EXAMPLES 58-71 Ion-Exchange Metal Ion Source

A metal citrate solution was prepared by adding approximately 4 grams of citric acid to about 8 grams of water and mixed until fully dissolved. Thereafter, 0.1 grams each of two ion-exchange type antimicrobial agents, AgION AC10D and AgION AK10D antimicrobial agents from AgION Technologies of Wakefield, Mass., USA, were added to the concentrated citric acid solution with agitation until the antimicrobial agents fully dissolved. Approximately 92 grams of water was then added to provide a 4% citric acid solution having dissolved therein 0.1 wt % AC10D and 0.1 wt % AK10D. AgION AK10D contains about 5.0% by weight silver and about 13% by weight zinc and AgION AC10D contains about 6.0% by weight copper and about 3.5% by weight silver. Various quantities of the so formed citric acid solution were then added to test vials so as to provide a silver content in the test vials of approximately 1.25 ppm, 2.5 ppm, 5.0 ppm and 10 ppm. Additionally, different surfactant and surfactant combinations were added to certain vials to demonstrate the effect of different metal and acid contents on bioefficacy with and without surfactants. The specific formulations evaluated and the yeast growth results are presented in Tables 4 and 4A.

As seen in Tables 4 and 4A, the compositions according to the present invention provided marked inhibition in yeast growth. Although Example 61 containing the higher concentration of metal ions (10 ppm silver, 7 ppm copper and 15.3 ppm zinc), showed good yeast growth inhibition, the higher degree of efficacy comes with the concomitant increase in the release of these metals into the environment. This becomes especially important where the bioactive materials are to be used in or near marine and/or agricultural applications. Thus, while high metal concentrations, especially of silver, will provide better bioefficacy, they also hasten the impact on aquatic environments. On the other hand, as shown in those examples employing the antimicrobial metal containing acid solutions with the anionic surfactant, especially sodium lauroyl sarcosinate, alone or in combination with sodium lauryl sulfate, the same and even better yeast inhibition is realized with less than half, even less than one-quarter, the metal ion concentrations. Furthermore, these results show that by adjusting the level of

TABLE 4 Turbidity (NTU) Example Ag Concentration ppm Surfactant* (wt %) OD (T zero) OD (T1 hr) OD (T18 hr) OD (T24 hr) OD (T44 hr) OD (T120 hr) 58 1.25 108 128 913 880 954 1136 59 2.5 127 157 865 890 941 1024 60 5 176 199 229 227 234 721 61 10 168 173 191 191 190 180 62 1.25 0.005 NaLS 143 158 240 560 843 708 63 2.5 0.005 NaLS 180 179 204 210 729 843 64 5 0.005 NaLS 194 201 222 221 227 227 65 1.25 0.005 SLS 136 167 953 930 973 1132 66 2.5 0.005 SLS 201 212 880 880 967 1145 67 5 0.005 SLS 248 247 272 272 296 297 68 1.25 .0025 NaLS/.0025 SLS 166 180 343 730 957 986 69 2.5 .0025 NaLS/.0025 SLS 215 217 235 239 759 940 70 5 .0025 NaLS/.0025 SLS 235 235 257 255 259 268 71 Control 101 125 1050 1050 1040 1183 *NaLS—sodium lauroyl sarcosinate, SLS—sodium lauryl sulfate

TABLE 4A Change in Turbidity (delta NTU) Example Ag Concentration ppm Surfactant* (wt %) OD (T1 hr) OD (T18 hr) OD (T24 hr) OD (T44 hr) OD (T120 hr) 58 1.25 20 805 772 846 1028 59 2.5 30 738 763 814 897 60 5 23 53 51 58 545 61 10 5 23 23 22 12 62 1.25 0.005 NaLS 15 97 417 700 565 63 2.5 0.005 NaLS −1 24 30 549 663 64 5 0.005 NaLS 7 28 27 33 33 65 1.25 0.005 SLS 31 817 794 837 996 66 2.5 0.005 SLS 11 679 679 766 944 67 5 0.005 SLS −1 24 24 48 49 68 1.25 .0025 NaLS/.0025 SLS 14 177 564 791 820 69 2.5 .0025 NaLS/.0025 SLS 2 20 24 544 725 70 5 .0025 NaLS/.0025 SLS 0 22 20 24 33 71 Control 24 949 949 939 1082 *NaLS—sodium lauroyl sarcosinate, SLS—sodium lauryl sulfate surfactant, one may reduce the level of metal ion even more while still providing marked inhibition of the fungi.

Also surprising about this example is the finding that citric acid could dissolve the antimicrobial zeolite particles. This finding presents another means by which the inventive compositions may be made as well as a number of alternative applications for such materials not otherwise possible with the zeolites in their solid form.

EXAMPLES 72-79 Metal Concentration

For this study a concentrated bioactive system (MI2) was prepared comprising a 16% aqueous citric acid solution having dissolved therein silver citrate, copper citrate and zinc citrate, each added in an amount to provide 200 ppm of each metal, together with 0.25% sodium Lauroyl sarcosinate and 0.32% sodium lauryl sulfate. Various amounts of this system were added to the test vials to further assess the impact of metal concentration yeast inhibition. A further example was prepared further including a non-ionic surfactant, Tween 20 (polyoxyethylene (20) sorbitan monolaurate), an emulsifier to assess its impact on performance. The specific formulations evaluated and the results are presented in Tables 5 and 5A.

As seen in Tables 5 and 5A, the high concentrations of metals dramatically inhibited, if not stopped altogether, yeast growth. The solutions of Examples 76, 77 and 78 containing ultra-high metal content appeared to destroy the yeast cells, showing what appeared to be a rapid denaturation of the yeast on addition of the bioactive material to the text vials. It is likely that the initial high turbidity reflected both that arising from the addition of the bioactive materials themselves as well as the destruction of the yeast cells.

Regardless, the results show that marked inhibition is also attained at much lower concentrations of the metal in the presence of the excess acid and surfactant. Indeed, just 15 ppm metals (5 ppm of each) provide excellent inhibition through 82 hours and beyond.

TABLE 5 Concen- MI2* tration of added each metal Turbidity (NTU) Example (ml) (ppm) T0 T18 T22 T24 T64 T82 72 0 0 63 920 980 964 1020 1050 73 0.1 1 81 608 722 820 1077 1062 74 0.25 2.5 111 126 142 160 752 810 75 0.5 5 145 198 208 208 205 203 76 1.0 10 483 410 395 369 320 300 77 2.0 20 1295 820 714 660 399 264 78 3.0 30 1435 766 620 555 340 340 79 0.5⁺ 5 141 249 405 600 1116 1129 *MI2 a 16% citric acid solution containing of 200 ppm each of Ag, Cu and Zn per ml ⁺this formulation also contained 0.1 wt % Tween 20 a non-ionic surfactant

TABLE 5A MI2* Concentration added of each metal Change in Turbidity (delta NTU) Example (ml) (ppm) T18 − T0 T22 − T0 T24 − T0 T64 − T0 T82 − T0 72 0 0 857 917 901 957 987 73 0.1. 1 527 641 739 996 981 74 0.25 2.5 15 31 49 641 699 75 0.5 5 53 63 63 60 58 76 1.0 10 −73 −88 −114 −163 −183 77 2.0 20 −475 −581 −635 −896 −1031 78 3.0 30 −669 −815 −880 −1095 −1095 79 0.5⁺ 5 108 264 459 975 988 *MI2 a 16% citric acid solution containing of 200 ppm each of Ag, Cu and Zn per ml ⁺this formulation also contained 0.1 wt % Tween 20 a non-ionic surfactant

Finally, the addition of Tween 20 surfactant appeared to be antagonistic to the action of the bioactive systems of the present invention resulting in a reduction in the level of yeast inhibition. Still, this composition (Example 79) manifested moderate yeast inhibition through 24 hours. Depending upon the specific end-use application contemplated, it is evident that routine preliminary evaluations should be conducted before formulating with various additives to ascertain their impact on the inventive systems of the present invention.

EXAMPLES 80-95 Bioactives Synergy

A series of experiments were conducted in which possible synergies were evaluated between the inventive compositions and other bioactive materials as well as between such other bioactive materials including a fungicide, an antimicrobial agent and a disinfectant. The inventive bioactive system employed in this set of experiments (MI3) was a 4% aqueous citric acid solution containing 50 ppm silver, 50 ppm copper and 50 ppm zinc.

The fungicide evaluated was Mancozeb Flowable with Zinc from Bonide Products, Inc. of Oniskany, N.Y., USA, a commercial formulated fungicide containing 37% by wt mancozeb. Although the specific formulation of the Mancozeb product is proprietary, as a commercial formulation it would also contain certain surfactants for enabling its application to plants for efficacy. Mancozeb is an insoluble, dispersible powder that increases the turbidity of the liquids to which it is added. Nevertheless, in a separate evaluation, not reproduced here, it was found that Mancozeb was able to control or inhibit yeast growth at a concentration of about 1.23×10⁻³. The label indicates its use rate at 2.6×10⁻³.

The antimicrobial active evaluated was AgION AC10D, an antimicrobial zeolite additive available from AgION Technologies, Inc., of Wakefield, Mass., USA, which, as noted above, contains 6.0 wt % copper and 3.5 wt % silver. In a separate dilution evaluation, not reproduced here, it was found that an aqueous suspension of AC10D showed some yeast control or inhibition at a concentration of about 6.25×10⁴.

Finally, the disinfectant evaluated was AgION SilverClene 24, a disinfectant material based on an aqueous solution of electrolytically generated silver citrate (˜30 ppm silver), also distributed by AgION Technologies, Inc. Although proprietary, this product and its manufacture is believed to be disclosed in Arata—U.S. Pat. No. 6,583,176, which is incorporated herein by reference in its entirety.

The aforementioned materials as well as various combinations thereof were evaluated to assess their efficacy in stopping or inhibiting the growth of yeast. The specific formulations tested and the yeast inhibition results attained therewith are presented in Tables 6 and 6A.

TABLE 6 Amt MI3 Mancozeb AgION AC10D SilverClene 24 Turbidity (NTU) Example (ml) (wt %) (wt %) (ml) Surfactant (wt %) OD T zero T (1 hour) T (18 hour) T (24 Hour) pH 80 9.40E−05 262 293 1023 1030 3.07 81 1 9.40E−05 276 276 309 522 2.91 82 2 9.40E−05 301 301 308 312 2.55 83 2 1.88E−04 0.05 NaLS/0.05 SLS 350 362 362 362 84 2 3.75E−04 656 640 1001 1170 2.4 85 1 9.40E−05 0.05 SLS 331 321 328 330 2.48 86 to pH 6 3.75E−04 0.05 NaLS/0.05 SLS 609 605 825 968 4.91 87 1.88E−04 7.81E−05 0.05 NaLS 410 385 443 511 88 2 1.88E−04 7.81E−05 0.05 NaLS/0.05 SLS 521 435 435 440 2.68 89 9.40E−05 1 258 276 970 962 2.67 90 1.88E−04 2 365 364 782 1048 91 3.90E−05 128 151 862 800 3.23 92 2 3.90E−05 0.05 SLS 154 156 172 175 2.54 93 2 1.56E−04 0.05 NaLS/0.05 SLS 190 143 148 156 2.66 94 2 0.05 NaLS/0.05 SLS 157 67 189 195 2.51 95 Control 73 98 898 856 3.25

TABLE 6A Change in Turbidity (delta NTU) Amt MI3 Mancozeb AgION AC10D SilverClene 24 1 − 18 24 1 − 24 Example (ml) (wt %) (wt %) (ml) Surfactant (wt %) 1 hour 18 hour hour hour hour 80 9.40E−05 31 761 730 768 737 81 1 9.40E−05 0 33 33 246 246 82 2 9.40E−05 0 7 7 11 11 83 2 1.88E−04 0.05 NaLS/0.05 SLS 12 12 0 12 0 84 2 3.75E−04 −16 345 361 514 530 85 1 9.40E−05 0.05 SLS −10 −3 7 −1 9 86 to pH 6 3.75E−04 0.05 NaLS/0.05 SLS −4 216 220 359 363 87 1.88E−04 7.81E−05 0.05 NaLS −25 33 58 101 126 88 2 1.88E−04 7.81E−05 0.05 NaLS/0.05 SLS −86 −86 0 −81 5 89 9.40E−05 1 18 712 694 704 686 90 1.88E−04 2 −1 417 416 683 682 91 3.90E−05 23 734 711 672 649 92 2 3.90E−05 0.05 SLS 2 18 16 21 19 93 2 1.56E−04 0.05 NaLS/0.05 SLS −47 −42 5 −34 13 94 2 0.05 NaLS/0.05 SLS −90 32 122 38 128 95 Control 25 825 800 783 758

The results presented in Tables 6 and 6A demonstrate a marked synergy between the inventive compositions according the present invention and commercial fungicides and antimicrobial agents. Specifically, for example, a comparison of the results for Examples 80, 81 and 82 demonstrate that combining low amounts of the metal ions, citric acid and fungicide provided excellent antifungal performance. While it is noted that these formulations did not have additional surfactant, the commercial fungicide itself contained surfactants that worked in combination with the metal ions and citric acid to provide the benefits owing to that combination as now claimed. These results show that excellent antifungal activity, as measured by yeast growth inhibition, may be attained with less than 10% of the amount of fungicide needed to inhibit yeast growth by the simple addition of low levels of acid and metal ions. As seen from Examples 91, 92 and 93, a similar synergy is shown for the inventive compositions in combination with a conventional inorganic antimicrobial agent. Here too, less than 10% of that amount of the antimicrobial agent needed when used alone, provided good antimicrobial performance when in combination with low levels of bioactive composition according to the present invention. However, the substitution of the SilverClene 24 for the inventive composition of the present invention, Examples 89 and 90, provided no apparent benefit despite the relatively high silver content.

Finally, in Example 86, ammonia was added to a portion of the MI3 solution until the solution reached a pH of 6. 2 ml of this buffered solution was then employed in the experiment. This example indicates the importance of the low pH of the compositions according to the present invention in order to provide desirable performance.

EXAMPLES 96-107 Immunox Synergy

A similar study was conducted to assess the synergy between the bioactive compositions according to the present invention and a second fungicide, Immunox, a commercial fungicide containing 1.55% myclobutanil, available from Spectrum Brands Division of United Industries of Madison, Wis., USA. As a commercial formulation, this too is expected to have some surfactants content. The bioactive composition employed in this experiment was the concentrated bioactive system (MI2) produced in Examples 72-79 above. The specific dilutions of each and the results attained thereby are presented in Table 7.

TABLE 7 Dilution Ratio T1.5 Delta Example Immunox MI2 T zero OD T18 T68 OD 68 96 1:80 150 152 832 682 97 1:200 106 112 980 874 98 1:64 97 107 1043 99 1:128 111 119 1126 100 1:256 84 131 1170 1086 101 1:512 81 140 1240 1159 102 1:256 1:80 138 141 268 130 103 1:256 1:200 102 114 1037 935 104 1:512 1:80 138 140 292 154 105 1:512 1:200 97 110 1031 934 106 Control 1 86 175 754 668 107 Control 2 87 176 1180 1093

As indicated in Table 7, none of the test vials containing the low levels of each of the bioactive compositions or the Immunox dilution provided antifungal activity through the full 96 hour period tested. Furthermore, neither the 1:128 dilution (Example 99) nor the 1:64 dilution (Example 98) of Immunox provided any measure of efficacy, even in the shorter test period of 18 hours, despite the fact that the manufacturer generally recommends a dilution of 1:64. Similarly, Examples 103 and 105 having a 1:200 dilution of the bioactive composition (˜1 ppm of each metal, 0.08% citric acid, 0.00125 NaLS and 0.0016 SLS) in combination with the two dilutions of the Immunox failed to demonstrate bioefficacy whereas combinations of both dilutions of the Immunox with a somewhat higher level, 1:80 dilution, of the bioactive composition (˜2.5 ppm of each metal, 0.2% citric acid, 0.003 NaLS and 0.004 SLS) demonstrated bioefficacy. This demonstrates a synergy between the two compositions as the 1:80 dilution by itself failed to show bioefficacy over the full period tested.

EXAMPLES 108-126 Metal Sources

A series of experiments were conducted using different metal salts as the metal ion sources. Here, sufficient amounts of silver nitrate, copper sulfate and zinc oxide were added to a 5% aqueous citric acid solution to provide 31.75 ppm silver, 12.5 ppm copper and 40.17 ppm zinc. Different quantities of this stock concentrate solution (MI4) were added to the test vials to assess efficacy. The specific formulations, including the resultant ppm of each metal in the text vial, as well as the results thereof in inhibiting yeast growth were as presented in Tables 8 and 8A.

The results shown in Tables 8 and 8A demonstrate that the selection of the metal ion source is not critical so long as it is readily soluble and is soluble to the extent needed to provide the desired level of metal ion concentration in the solution. Furthermore, the results demonstrate the bioefficacy even at extremely low metal and acid contents. Although, the efficacy is relatively short lived at the lower concentrations, long-term bioefficacy is found with only minor adjustments in the relative concentration of the necessary components. Furthermore, depending upon the ultimate end-use application, such short term antifungal efficacy may be sufficient; thus, enabling one to minimize any environmental contamination from the general application of these materials.

The results also suggest that sodium lauryl sulfate may be ineffective on its own in promoting the bioefficacy of the bioactive compositions of the present invention. Nevertheless, its presence may be desirable where the efficacious surfactant is not readily soluble in the aqueous system. On the other hand, its presence or the presence of like surfactants may not be important where the intent is to produce non-aqueous systems. For example, systems to be applied as an emulsion in water or as an oil that will spread on an aqueous medium to which it is applied, e.g., a rice paddy, may look to surfactants that are less hydrophilic and more lipophilic.

EXAMPLES 127-143 Lactic Acid

A series of experiments was conducted similar to the previous with the exception that lactic acid was substituted for citric acid. Hence, the bioactive composition (MI5) comprised sufficient amounts of silver nitrate, copper sulfate and zinc oxide dissolved in a 5% aqueous lactic acid solution to provide 31.75 ppm silver, 12.5 ppm copper and 40.17 ppm zinc. The specific formulations tested and the results attained therewith were as presented in Tables 9 and 9A.

TABLE 8 Surfactant Volume MI4 Metals Concentration (w/w)% Turbidity (NTU) Example added ppm Ag ppm Cu ppm Zn NaLS SDS T zero T2 T18 T26 T44 T48 T68 108 0.5 0.79 0.31 1.00 81 129 950 1046 1046 1046 1054 109 1 1.59 0.63 2.01 85 136 950 997 1055 990 1023 110 2 3.18 1.25 4.02 112 158 916 930 960 930 970 111 3 4.76 1.88 6.03 126 158 760 799 810 830 844 112 0.5 0.79 0.31 1.00 0.005 140 143 179 307 919 936 980 113 1 1.59 0.63 2.01 0.005 140 137 143 152 279 306 468 114 2 3.18 1.25 4.02 0.005 180 174 174 177 244 252 282 115 3 4.76 1.88 6.03 0.005 187 185 184 184 184 184 272 116 0.5 0.79 0.31 1.00 0.005 83 132 948 1054 1066 1078 1097 117 1 1.59 0.63 2.01 0.005 97 136 911 1003 1100 1060 1075 118 2 3.18 1.25 4.02 0.005 116 147 746 907 970 1001 1006 119 3 4.76 1.88 6.03 0.005 124 156 504 701 840 868 916 120 0.5 0.79 0.31 1.00 0.0025 0.0025 140 140 250 640 1065 1088 1133 121 1 1.59 0.63 2.01 0.0025 0.0025 149 149 160 256 930 901 1014 122 2 3.18 1.25 4.02 0.0025 0.0025 164 177 174 174 291 459 804 123 3 4.76 1.88 6.03 0.0025 0.0025 176 179 177 181 320 445 736 124 2 3.18 1.25 4.02 0.01 162 162 162 163 163 164 164 125 0.86 1.37 0.54 1.73 0.01 150 140 140 140 186 208 254 126 78 113 877 866 878 865 898

TABLE 8A Volume Metals Surfactant Change in Turbidity (delta NTU) MI4 Concentration (w/w)% Delta Example added ppm Ag ppm Cu ppm Zn NaLS SDS T2 − T0 DT18 − T0 DT26 − T0 DT44 − T0 DT48 − T0 DT68 − T0 108 0.5 0.79 0.31 1.00 48 869 965 965 965 973 109 1 1.59 0.63 2.01 51 865 912 970 905 938 110 2 3.18 1.25 4.02 48 804 818 848 818 858 111 3 4.76 1.88 6.03 32 624 673 684 704 718 112 0.5 0.79 0.31 1.00 0.005 3 39 167 779 796 840 113 1 1.59 0.63 2.01 0.005 −3 3 12 139 166 328 114 2 3.18 1.25 4.02 0.005 −8 −6 −3 64 72 102 115 3 4.76 1.88 6.03 0.005 −2 −3 −3 −3 −3 85 116 0.5 0.79 0.31 1.00 0.005 49 865 971 983 995 1014 117 1 1.59 0.63 2.01 0.005 39 814 906 1003 963 978 118 2 3.18 1.25 4.02 0.005 31 630 791 854 885 890 119 3 4.76 1.88 6.03 0.005 32 380 577 716 744 792 120 0.5 0.79 0.31 1.00 0.0025 0.0025 0 110 500 925 948 993 121 1 1.59 0.63 2.01 0.0025 0.0025 0 11 107 781 752 865 122 2 3.18 1.25 4.02 0.0025 0.0025 13 10 10 127 295 640 123 3 4.76 1.88 6.03 0.0025 0.0025 3 1 5 144 269 560 124 2 3.18 1.25 4.02 0.01 0 0 1 1 2 2 125 0.86 1.37 0.54 1.73 0.01 −10 −10 −10 36 58 104 126 35 799 788 800 787 820

TABLE 9 Surfactant Volume MI5 Metals Concentration (w/w)% Turbidity (NTU) Example added ppm Ag ppm Cu ppm Zn NaLS SDS T zero T1 T18 T24 T44 127 0.5 0.79 0.31 1.00 107 130 1000 1111 1001 128 1 1.59 0.63 2.01 109 130 1006 1021 1016 129 2 3.18 1.25 4.02 148 154 970 995 1014 130 3 4.76 1.88 6.03 178 202 914 925 990 131 0.5 0.79 0.31 1.00 0.005 134 170 300 454 923 132 1 1.59 0.63 2.01 0.005 153 169 200 227 292 133 2 3.18 1.25 4.02 0.005 218 217 207 204 228 134 3 4.76 1.88 6.03 0.005 222 223 222 215 227 135 0.5 0.79 0.31 1.00 0.005 120 145 1074 1111 1079 136 1 1.59 0.63 2.01 0.005 140 156 1050 1092 1110 137 2 3.18 1.25 4.02 0.005 179 193 945 1031 1080 138 3 4.76 1.88 6.03 0.005 223 239 690 977 1180 139 0.5 0.79 0.31 1.00 0.0025 0.0025 143 151 884 968 1170 140 1 1.59 0.63 2.01 0.0025 0.0025 175 175 237 330 1110 141 2 3.18 1.25 4.02 0.0025 0.0025 210 214 207 223 730 142 3 4.76 1.88 6.03 0.0025 0.0025 240 240 228 228 475 143 control 100 139 1175 1163 1170

TABLE 9A Surfactant Volume MI5 Metals Concentration (w/w)% Change in Turbidity (delta NTU) Example added ppm Ag ppm Cu ppm Zn NaLS SDS DT1 − T0 DT18 − T10 DT24 − T0 DT44 − T0 127 0.5 0.79 0.31 1.00 23 893 1004 894 128 1 1.59 0.63 2.01 21 897 912 907 129 2 3.18 1.25 4.02 8 822 847 866 130 3 4.76 1.88 6.03 24 736 747 812 131 0.5 0.79 0.31 1.00 0.005 36 166 320 789 132 1 1.59 0.63 2.01 0.005 16 47 74 139 133 2 3.18 1.25 4.02 0.005 −1 −11 −14 10 134 3 4.76 1.88 6.03 0.005 1 0 −7 5 135 0.5 0.79 0.31 1.00 0.005 25 954 991 959 136 1 1.59 0.63 2.01 0.005 16 910 952 970 137 2 3.18 1.25 4.02 0.005 14 766 852 901 138 3 4.76 1.88 6.03 0.005 16 467 754 957 139 0.5 0.79 0.31 1.00 0.0025 0.0025 8 741 825 1027 140 1 1.59 0.63 2.01 0.0025 0.0025 0 62 155 935 141 2 3.18 1.25 4.02 0.0025 0.0025 4 −3 13 520 142 3 4.76 1.88 6.03 0.0025 0.0025 0 −12 −12 235 143 control 39 1075 1063 1070

TABLE 10 Turbidity (NTU Example Metal source Metal (ppm) Surfactants (w/w) T zero T 1 hour T18 T24 T42 T48 T72 T96 144 Citrate salts* 2.5 123 134 300 400 1046 1094 1146 1106 145 Citrate salts* 5 199 180 166 166 160 163 162 154 146 Citrate salts* 10 211 193 176 176 172 177 172 169 147 AgNO3, CuSO4, ZnO 2.5 168 166 179 179 172 174 778 1162 148 AgNO3, CuSO4, ZnO 5 209 193 180 180 175 174 170 168 149 AgNO3, CuSO4, ZnO 10 228 219 197 197 196 204 199 194 150 Citrate salts* 5 0.05 SLS 226 218 200 200 193 203 192 186 151 Citrate salts* 5 0.05 NaLS 258 254 216 216 200 205 197 185 152 Citrate salts* 5 0.05 SLS/0.05 NaLS 253 237 200 200 204 208 201 188 153 AgNO3, CuSO4, ZnO 5 0.05 SLS 285 263 229 229 223 229 214 206 154 AgNO3, CuSO4, ZnO 5 0.05 NaLS 280 273 226 222 216 213 208 184 155 AgNO3, CuSO4, ZnO 5 0.05 SLS/0.05 NaLS 283 272 250 247 232 238 232 215 156 Control 52 53 437 599 938 913 877 886 *Ag citate, Cu citrate and Zn citrate, each at level designated

TABLE 10A Metal Change in Turbidity (delta NTU) Example Metal source (ppm) Surfactants (w/w) T1 − T0 T18 − T1 T24 − T1 T42 − T1 T48 − T1 T72 − T1 T96 − T1 144 Citrate salts* 2.5 11 166 266 912 960 1012 972 145 Citrate salts* 5 −19 −14 −14 −20 −17 −18 −26 146 Citrate salts* 10 −18 −17 −17 −21 −16 −21 −24 147 AgNO3, CuSO4, ZnO 2.5 −2 13 13 6 8 612 996 148 AgNO3, CuSO4, ZnO 5 −16 −13 −13 −18 −19 −23 −25 149 AgNO3, CuSO4, ZnO 10 −9 −22 −22 −23 −15 −20 −25 150 Citrate salts* 5 0.05 SLS −8 −18 −18 −25 −15 −26 −32 151 Citrate salts* 5 0.05 NaLS −4 −38 −38 −54 −49 −57 −69 152 Citrate salts* 5 0.05 SLS/0.05 NaLS −16 −37 −37 −33 −29 −36 −49 153 AgNO3, CuSO4, ZnO 5 0.05 SLS −22 −34 −34 −40 −34 −49 −57 154 AgNO3, CuSO4, ZnO 5 0.05 NaLS −7 −47 −51 −57 −60 −65 −89 155 AgNO3, CuSO4, ZnO 5 0.05 SLS/0.05 NaLS −11 −22 −25 −40 −34 −40 −57 156 Control 1 384 546 885 860 824 833

The results as shown in Tables 9 and 9A, mimic those found in the previous set of experiments indicating that the invention is translatable to acids of similar characteristics.

EXAMPLES 144-156 Phosphoric Acid

Two stock solutions were prepared for evaluation wherein the acid employed was phosphoric acid. In the first, silver citrate, copper citrate and zinc citrate were added to a 16% aqueous phosphoric acid solution to provide 200 ppm of each metal. A second stock solution was prepared using silver nitrate, copper sulfate and zinc oxide, again in the 16% phosphoric acid solution to provide 200 ppm of each metal. Both composition further contained 0.32% surfactant, either as an individual surfactant or as a 50:50 mix. The specific formulations and the results of their efficacy in controlling yeast growth were as presented in Tables 10 and 10A.

The results as shown in Tables 10 and 10A suggest that the surfactant may not be critical in those compositions wherein the excess acid is a strong to moderate acid, such as phosphoric acid.

EXAMPLES 157-166 Nitric Acid

To further demonstrate the breadth of the bioactive compositions, a relatively strong mineral acid, nitric acid, was employed as the acid component. A stock solution was prepared by combining 78.7 mg sliver nitrate, 62.2 mg zinc oxide and 200 mg copper sulfate with 20 ml of purified water and 1.5 g concentrated nitric acid (68%) under constant agitation. Once the solids were dissolved, additional purified water was added to make up a 250 volume. As prepared, this mixture contained approximately 200 ppm of each metal, as calculated. The pH was measured and found to be 1.66. The mixture was then divided into three aliquots of approximately equal volume. One aliquot was set aside and the other two were subjected to pH adjustment with ammonia hydroxide. The amount of ammonia hydroxide was added was that necessary to bring the pH of the first aliquot up to 2.55 and the second aliquot up to 3.63.

Each solution was then evaluated, with and without surfactants, to assess their bioefficacy in inhibiting the growth of yeast. The amount of each of the three aliquots added to the 20 ml vial of the yeast suspension is set forth in

TABLE 12 Example Surfactants Surfactant Chemistry Source Type Metal ppm 167 Pluronic L62 E0-PO Block copolymer BASF Nonionic 0 168 2.5 169 5 170 Hampopsyl L95 Na N-lauroyl Sarcosinate Hampshire Chemical Anionic 0 171 2.5 172 5 173 Sodium Lauryl Sulfate Sodium Lauryl Sulfate VWR Scientific Anionic 0 174 2.5 175 5 176 Witco Sodium Laurylether Sulfate Witco Chemical Anionic 0 177 (2 mole EO) 2.5 178 5 179 Jeenteric CAPB LC Cocamidopropyl betaine Jeen International Corp Amphoteric 0 180 2.5 181 5 182 Manckinate LO100 DLSS Dilauryl sulfosuccinate Mackintire Chemical amphoteric 0 183 2.5 184 5 185 Ammonyx LO Lauryl Dimethyamine Oxide Stepan Chemical Nonionic 0 186 2.5 187 5 188 Hamposyl C30 Na N-cocoyl Sarcosinate Hampshire Chemical Anionic 0 189 2.5 190 5 191 Hamposyl M30 Na N-myristoyl Sarcosinate Hampshire Chemical Anionic 0 192 2.5 193 5 194 Hampshire TL Glutamate TEA lauroyl Glutamate Hampshire Chemical Anionic 0 195 2.5 196 5 197 Tergitol 15S3 Secondary Alcohol Ethoxylate Dow Chemical Nonionic 0 198 2.5 199 5 200 Tergitol 15S7 Secondary Alcohol Ethoxylate Dow Chemical Nonionic 0 201 2.5 202 5 203 Tergitol TMN6 Branched Secondary Alcohol Dow Chemical Nonionic 0 204 Ethoxylate 2.5 205 5 206 Tergitol TMN3 Branched Secondary Alcohol Dow Chemical Nonionic 0 207 Ethoxylate 2.5 208 5 209 Sulfonic TDA3B C1-C14 Ethoxylated Alcohol Huntsman Chemical Nonionic 0 210 2.5 211 5 212 Tween 20 polyoxyethylene (20) sorbitan Nonionic 0 213 monolaurate 2.5 214 5 215 Plantaren 2000 Alkyl polyglycoside Cognis Nonionic 0 216 2.5 217 5 218 Control 0 219 Control (2.5 ppm) 0 220 Control (5 ppm) 0 221 Metals Control 2.5 222 Metals Control 5 Example T0 T18 T48 T72 T96 T18 − T0 T48 − T0 T72 − T0 T96 − T0 167 47 1088 1113 1142 1156 1041 1066 1095 1109 168 343 376 362 364 340 33 19 2 −24 169 118 1127 1138 1175 1146 1009 1020 1057 1028 170 47 42 390 884 878 −5 343 837 831 171 70 909 999 1037 983 839 929 967 913 172 407 444 442 440 440 37 35 33 33 173 48 495 658 642 639 447 610 594 591 174 88 90 88 88 87 2 0 0 −1 175 231 244 233 238 232 13 2 7 1 176 48 1060 1021 957 923 1012 973 909 875 177 73 819 1415 1436 1447 746 1342 1363 1374 178 140 143 446 870 915 3 306 730 775 179 48 645 657 882 462 597 609 834 414 180 93 90 91 90 88 −3 −2 −3 −5 181 204 204 202 202 202 0 −2 −2 −2 182 95 1020 866 817 788 925 771 722 693 183 118 97 106 1165 1317 −21 −12 1047 1199 184 251 239 232 224 215 −12 −19 −27 −36 185 44 28 35 45 28 −16 −9 1 −16 186 972 390 118 115 105 −582 −854 −857 −867 187 652 314 252 227 180 −338 −400 −425 −472 188 44 207 1043 1041 1037 163 999 997 993 189 699 677 657 673 1115 −22 −42 −26 416 190 510 554 576 589 593 44 66 79 83 191 46 28 152 1205 1184 −18 106 1159 1138 192 588 564 1372 1385 1389 −24 784 797 801 193 583 586 1299 1382 1383 3 716 799 800 194 66 946 977 927 905 880 911 861 839 195 182 410 1143 1189 1178 228 961 1007 996 196 218 618 1104 1129 1162 400 886 911 944 197 188 1140 1178 969 880 952 990 781 692 198 180 340 1247 1227 1134 160 1067 1047 954 199 317 818 1350 1297 1289 501 1033 980 972 200 48 865 1077 766 577 817 1029 718 529 201 91 117 1152 1087 917 26 1061 996 826 202 197 408 1291 1224 1217 211 1094 1027 1020 203 50 940 1128 784 614 890 1078 734 564 204 106 132 1184 1140 1048 26 1078 1034 942 205 215 480 1300 1275 1266 265 1085 1060 1051 206 49 314 1015 700 541 265 966 651 492 207 92 94 1054 1014 876 2 962 922 784 208 189 247 1100 1128 1128 58 911 939 939 209 206 1163 1183 948 809 957 977 742 603 210 260 372 1296 1248 1192 112 1036 988 932 211 359 725 1369 1366 1319 366 1010 1007 960 212 57 1077 1118 1087 730 1020 1061 1030 673 213 92 932 1116 867 719 840 1024 775 627 214 169 1080 1144 1105 1048 911 975 936 879 215 56 346 906 782 642 290 850 726 586 216 102 410 660 1104 1323 308 558 1002 1221 217 229 235 232 232 237 6 3 3 8 218 58 1171 1152 1168 1177 1113 1094 1110 1119 219 94 968 1073 1180 1041 874 979 1086 947 220 132 1196 1185 1228 1233 1064 1053 1096 1101 221 93 1001 1080 1128 962 908 987 1035 869 222 152 1160 1186 1228 1193 1008 1034 1076 1041 Table 11 together with the amount of surfactant added, where indicated. The surfactant employed was a 50:50 mix of sodium lauryl sulfate and sodium lauroyl sarcosinate. The specific formulations tested and the results thereof are presented in Table 11. As can be seen from Table 11, the combination of metal and acid did not provide any inhibition at the levels tested. However, when the surfactant was added, bioefficacy was manifested even at the lower metal/acid concentration.

TABLE 11 Nitric Acid Vol. MI6 Metals Surfactant Turbidity/Change in Turbidity Example Added (ppm) (w/w) % pH T0 T18 T18 − T0 T42 T42 − T0 157 0.5 5 1.66 69 1243 1174 1133 1064 158 0.5 5 2.55 67 1245 1178 1133 1066 159 0.5 5 3.63 69 1243 1174 1150 1081 160 1 10 1.66 65 976 911 1162 1097 161 1 10 2.55 66 1012 946 1186 1120 162 1 10 3.63 67 1036 969 1166 1099 163 0.5 5 0.05 1.66 61 55 −6 58 −3 164 0.5 5 0.05 2.55 62 53 −9 55 −7 165 0.5 5 0.05 3.63 60 57 −3 52 −8 166 0 67 1255 1188 1212 1145

EXAMPLES 167-222 Surfactant Evaluation

A series of experiments were conducted to screen various surfactants for efficacy in accordance with the present invention. The surfactants were evaluated as a neat additive (0 ppm metals) or in combination with either 1 ml or 2 ml of a 4% citric acid solution containing 50 ppm each of copper, silver and zinc. With the addition of 1 ml of the citric acid solution, the test vial of the yeast suspension will have about 0.2% citric acid and about 2.5 ppm of each metal. With the addition of 2 ml of the citric acid solution, the acid is approximately 0.4% and the metals are each present at about 5 ppm in the test vials. Each surfactant was evaluated at a concentration of approximately 0.05 wt %. Controls were also evaluated with and without the metals.

The specific surfactants evaluated as well as the formulations of each test composition together with the results thereof are set forth in Table 12. As

TABLE 13 Turbidity (NTU) Example Fungicide vol. Added T0 T1 T18 T26 T50 223 Quadris^(a) 1 384 393 1066 1139 1134 224 2 767 772 1264 1311 1315 225 5 1332 1332 1364 1377 1376 226 Flint^(b) 1 418 424 1115 1208 1234 227 2 718 708 1141 1299 1327 228 5 1210 1210 1270 1265 1245 229 Headline^(c) 1 232 225 961 1114 1137 230 2 387 391 1066 1134 1199 231 5 717 747 1178 1222 1241 232 MI2 0.5 128 129 154 177 174 233 MI2 1 414 384 366 366 352 234 MI7 0.5 249 244 248 248 242 235 MI7 1 311 302 283 283 277 236 Control 67 68 793 871 904 ^(a)Quadris fungicide from Syngenta Crop Protections, Inc. of Greensboro, NC, USA ^(b)Flint fungicide from Bayer CropScience LP of Research Triangle Park, NC, USA ^(c)Headline from BASF Corporation of Research Triangle Park, NC, USA

TABLE 13A Change in Turbidity (delta NTU) Example Fungicide vol. Added T18 − T1 T26 − T1 T50 − T1 223 Quadris^(a) 1 673 746 741 224 2 492 539 543 225 5 32 45 44 226 Flint^(b) 1 691 784 810 227 2 433 591 619 228 5 60 55 35 229 Headline^(c) 1 736 889 912 230 2 675 743 808 231 5 431 475 494 232 MI2 0.5 25 48 45 233 MI2 1 −18 −18 −32 234 MI7 0.5 4 4 −2 235 MI7 1 −19 −19 −25 236 Control 725 803 836 ^(a)Quadris fungicide from Syngenta Crop Protections, Inc. of Greensboro, NC, USA ^(b)Flint fungicide from Bayer CropScience LP of Research Triangle Park, NC, USA ^(c)Headline from BASF Corporation of Research Triangle Park, NC, USA seen in Table 12, the benefits of the present invention are realized with a broad array of surfactant materials. Especially preferred surfactants are those that are free or substantially free of repeat ethylene oxide units and/or have moderate to lower molecular weights. Despite the foregoing, it is noted that good results were attained with the Pluronic L62, a polyethylene oxide containing surfactant, when used in combination with the lower level of acid and metals. It is thought that the higher acid level may have affected the stability of this material, and possibly like materials.

EXAMPLES 223-236 Strobilurin Comparison

A series of experiments were conducted in order to evaluate the comparative performance of the bioactive compositions of the present invention and several commercial strobilurin based fungicides. Two bioactive formulations were used. The first, MI2, comprised a 16% aqueous citric acid solution having dissolved therein silver citrate, copper citrate and zinc citrate, each being added in an amount to provide 200 ppm of each metal, together with 0.25% sodium Lauroyl sarcosinate and 0.32% sodium lauryl sulfate, as noted above. The second, MI7, comprised a 160:1 dilution of a 16% aqueous phosphoric acid solution having dissolved therein silver citrate, copper citrate and zinc citrate, each being added in an amount to provide 200 ppm of each metal in the phosphoric acid solution. Each fungicide was evaluated at different levels. The specific formulations tested and the results attained therewith are presented in Tables 13 and 13A.

As seen in Tables 13 and 13A, the bioactive compositions of the present invention provided marked inhibition of yeast growth, even at the lower concentrations, ˜5 ppm of each metal ion. On the other hand, all but two of the strobilurin based fungicide formulations tested failed to demonstrate any significant bioefficacy against yeast over the time period tested. The two formulations that provided good inhibition were at comparatively high loadings.

EXAMPLES 237-250 Strobilurin Synergy

In light of the foregoing poor performance of the strobilurins generally, a series of experiments were conducted in order to evaluate the potential synergy between the bioactive compositions of the present invention and the foregoing commercial strobilurin based fungicides. The compositions employed were the

TABLE 14 Turbidity (NTU) Example Bioactive Vol. Added Fungicide^(a) Vol. Added T0 T1 T18 T24 T96 237 MI2 0.25 Q 1 552 554 544 670 1315 238 MI2 0.25 Q 2 896 894 868 891 1470 239 MI2 0.5 Q 1 588 578 564 564 608 240 MI2 0.25 F 1 578 599 568 568 1320 241 MI2 0.25 F 2 900 900 886 886 1330 242 MI2 0.25 H 1 436 433 454 454 1312 243 MI2 0.25 H 2 611 637 667 632 1302 244 MI7 0.25 Q 1 558 574 640 668 1273 245 MI7 0.25 F 1 517 560 990 1197 1396 246 MI7 0.25 H 1 465 476 605 587 1290 247 Control — 93 101 901 986 1075 248 MI2 0.5 499 440 390 390 373 249 MI2 0.25 182 179 175 176 1122 250 MI2 0.5 262 260 260 275 275 ^(a)Q—Quadris fungicide from Syngenta Crop Protections, Inc. of Greensboro, NC, USA; F—Flint fungicide from Bayer CropScience LP of Research Triangle Park, NC, USA; and H—Headline from BASF Corporation of Research Triangle Park, NC, USA

TABLE 14A Change in Turbidity (delta NTU) Example Bioactive Vol. Added Fungicide^(a) Vol. Added T18 − T1 T24 − T1 T96 − T1 237 MI2 0.25 Q 1 −10 116 761 238 MI2 0.25 Q 2 −26 −3 576 239 MI2 0.5 Q 1 −14 −14 30 240 MI2 0.25 F 1 −31 −31 721 241 MI2 0.25 F 2 −14 −14 430 242 MI2 0.25 H 1 21 21 879 243 MI2 0.25 H 2 30 −5 665 244 MI7 0.25 Q 1 66 94 699 245 MI7 0.25 F 1 430 637 836 246 MI7 0.25 H 1 129 111 814 247 Control — 800 885 974 248 MI2 0.5 −50 −50 −67 249 MI2 0.25 −4 −3 943 250 MI2 0.5 0 15 15 ^(a)Q—Quadris fungicide from Syngenta Crop Protections, Inc. of Greensboro, NC, USA; F—Flint fungicide from Bayer CropScience LP of Research Triangle Park, NC, USA; and H—Headline from BASF Corporation of Research Triangle Park, NC, USA same as used in the previous set of examples. The specific formulations tested and the results attained therewith are presented in Tables 14 and 14A.

As seen in Tables 14 and 14A, the combination of the bioactive compositions of the present invention with the strobilurin products produced a synergy whereby even the lowest levels of the strobilurin products tested produced a significant inhibition in yeast growth, even though these products appear to increase yeast growth when used alone, as shown in the Tables 13 and 13A.

EXAMPLES 251-259 Copper/Zinc Study

A series of experiments were conducted to demonstrate the bioefficacy of binary metal systems as compared to the ternary system used in most other examples. Here a solution of MI2 was compared to a similar composition containing 300 ppm of copper and 300 ppm of zinc (i.e., a 16% aqueous citric acid solution having dissolved therein copper citrate and zinc citrate, each being added in an amount to provide 300 ppm of each metal, together with 0.25% sodium Lauroyl sarcosinate and 0.32% sodium lauryl sulfate). The two bioactive compositions were evaluated at different loadings to assess their bioefficacy. The specific formulations tested and the results attained therewith are presented in Tables 15 and 15A.

As seen in Tables 15 and 15A, both the binary (copper/zinc-Cu/Zn) and the MI2 ternary silver/copper/zinc antimicrobial bioactive compositions demonstrated comparable bioefficacy in inhibiting the growth of yeast.

TABLE 15 Composition (gm) Example Cu/Zn MI2 T0 T1 T18 T24 T46 251 1 776 586 468 463 436 252 0.5 292 269 250 250 245 253 0.2 147 162 772 1055 1075 254 0.1 93 125 1076 1070 1036 255 Control 66 127 1020 1012 1137 256 1 830 633 547 522 500 257 0.5 335 320 292 302 284 258 0.2 152 178 512 1064 1098 259 0.1 90 136 1083 1087 1067

TABLE 15A Composition (gm) Cu/Zn MI2 T1 − T0 T18 − T0 T24 − T0 T46 − T0 251 1 −190 −118 −5 −27 252 0.5 −23 −19 0 −5 253 0.2 15 610 283 20 254 0.1 32 951 −6 −34 255 Control 61 893 −8 125 256 1 −197 −86 −25 −22 257 0.5 −15 −28 10 −18 258 0.2 26 334 552 34 259 0.1 46 947 4 −20

EXAMPLES 260-269 Mancozeb Synergy

A further series of experiments were conducted to assess the bioefficacy, especially the synergy, of the bioactive agrichemical composition containing Mancozeb (an ethylene bisdithiocarbamate) and the MI2 bioactive acid solution (MI2). The specific formulations tested and the results attained therewith are presented in Table 16 and 16A.

TABLE 16 Composition (gm) Example Mancozeb MI2 T0 T2 T18 T24 T44 260 0.5 934 976 1220 1095 1091 261 0.4 780 859 1021 982 1052 262 0.3 624 717 1209 1067 1113 263 0.2 392 489 1035 933 1073 264 0.2 57 55 54 72 756 265 0.5 0.2 930 897 864 839 788 266 0.4 0.2 727 709 684 664 591 267 0.3 0.2 537 555 535 509 460 268 0.2 0.2 370 369 370 343 331 269 Control 23 106 935 824 917

TABLE 16A Composition (gm) T2 − Example Mancozeb MI2 T0 T18 − T0 T24 − T0 T44 − T0 260 0.5 42 286 161 157 261 0.4 79 241 202 272 262 0.3 93 585 443 489 263 0.2 97 643 541 681 264 0.2 −2 −3 15 699 265 0.5 0.2 −33 −66 −91 −142 266 0.4 0.2 −18 −43 −63 −136 267 0.3 0.2 18 −2 −28 −77 268 0.2 0.2 −1 0 −27 −39 269 Control 83 912 801 894

As seen in Tables 16 and 16A, the mancozeb by itself was ineffective at all levels tested. The bioactive acid solution by itself provided modest bioefficacy, in spite of the very low level of antimicrobial metal ions; however, the suitable bioefficacy appeared to have been lost after 44 hours. In sharp contrast, the combination of the two, at all levels of the mancozeb, demonstrated excellent bioefficacy, even after 44 hours.

EXAMPLES 270-293 Amine Oxide Surfactant Study

A series of experiments were conducted to demonstrate the bioefficacy of amine oxide surfactants, specifically, lauryl dimethyl amine oxide (LDAO), alone and in combination with sodium lauroyl sarcosinate (NaLS) and/or sodium lauryl sulfate (SLS). In this instance a very dilute antimicrobial metal-acid solution was employed: 0.08% citric acid and 1 ppm each of silver, copper and zinc. The surfactants were employed at different levels to assess the lowest concentration at which synergy is realized. The specific formulations tested and the results attained therewith are presented in Table 17.

As seen in Table 17, even at such low concentration of acid and metal, the addition of only 0.0025% lauryl dimethyl amine oxide surfactant showed bioefficacy, with modest bioefficacy at the 0.00125% level with sodium lauroyl sarcosinate or the combination of sodium lauroyl sarcosinate and/or sodium lauryl sulfate. At 0.0025% lauryl dimethyl amine oxide, marked bioefficacy

TABLE 17 LDAO NaLS SLS AG, Cu, Zn Example (w/w) % (w/w) % (w/w) % ppm T zero T1 T42 T66 T42 − T1 T66 − T1 270 0.00025 132 219 1145 1133 926 914 271 0.00125 141 211 1120 1039 909 828 272 0.0025 161 196 862 814 666 618 273 0.00025 1 142 209 1108 1138 899 929 274 0.00125 1 144 208 1080 1076 872 868 275 0.0025 1 156 208 963 969 755 761 276 144 239 1232 1216 993 977 277 0.00025 0.00025 144 217 1084 1042 867 825 278 0.00125 0.00125 136 169 860 784 691 615 279 0.0025 0.0025 136 136 562 543 426 407 280 0.00025 0.00025 1 150 216 1032 1021 816 805 281 0.00125 0.00125 1 165 186 872 852 686 666 282 0.0025 0.0025 1 174 184 181 295 −3 111 283 0.00025 149 248 1138 1165 890 917 284 0.00125 142 202 1019 1018 817 816 285 0.0025 147 207 1034 1007 827 800 286 1 153 242 1167 1178 925 936 287 165 270 1223 1207 953 937 288 0.00025 0.00025 0.00025 178 272 1094 1006 822 734 289 0.00125 0.00125 0.00125 167 242 800 686 558 444 290 0.0025 0.0025 0.0025 224 212 605 550 393 338 291 0.00025 0.00025 0.00025 1 171 252 1039 1010 787 758 292 0.00125 0.00125 0.00125 1 260 258 862 872 604 614 293 0.0025 0.0025 0.0025 1 264 257 242 242 −15 −15 was found with addition of sodium lauroyl sarcosinate and superior bioefficacy found with addition of both sodium lauroyl sarcosinate and sodium lauryl sulfate.

Antibacterial Study EXAMPLES 294-325

A series of experiments were conducted to evaluate the performance of the individual components of the claimed bioactive compositions as well as various combinations thereof, including, the claimed compositions themselves, in suppressing the growth of various bacteria. Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were selected as a test organisms as they are generally accepted in the industry as indicator organisms for a wide variety of bacteria. Two different test methodologies were evaluated, one testing the efficacy in a growth broth media and the other testing inhibition in plated growth media.

EXAMPLES 294-305

In the first set of experiments a growth medium was prepared by adding 10 grams of nutrient medium (Difco Sabouraud dextrose broth from BD of Franklin Lakes, N.J., USA) to 300 ml of distilled water. The 20 ml aliquots of the growth medium were dispensed into sterile into 40 ml borosilicate glass vials with Teflon lined caps (VWR International Cat. No. 15900-004). The vials were inoculated with the bacteria using a sterile loop and the vials then incubated at 37° C. A bioactive composition according to the invention was then added to certain vials, the bioactive composition was (MI2), as described above, comprising a 16% aqueous citric acid solution having dissolved therein silver citrate, copper citrate and zinc citrate, each added in an amount to provide 200 ppm of each metal, together with 0.25% sodium Lauroyl sarcosinate and 0.32% sodium lauryl sulfate. The turbidity of each mixture was then determined and the vial transferred to an incubator at 30° C. Turbidity measurements were performed as in the above cited yeast studies. Each vial was periodically removed from the incubator and the mixture in the vials assessed for turbidity. The specific formulations tested, the timing for each turbidity evaluation, and the results attained thereby were as set forth in Table 18.

As with the yeast study, the concentration of the metals refers the approximate amount of each metal, copper, silver and zinc. The concentrations do not account for the volume of MI2 added: thus, the concentrations presented are on the basis of a 20 ml total volume.

As seen in Table 18, there was short term increase in turbidity. Since it was not anticipated that any significant growth would have manifested in such a short period of time, it is believed that the initial increase in turbidity resulted from a denaturation of proteins in the broth and/or bacterial proteins. Regardless, the longer term results show excellent bacterial inhibition with the compositions according to the present invention.

TABLE 18 MI2 Metals Time (hours) Example Bacterium (ml) ppm T0 T0.5 T18 T24 T96 294 E. coli 0 0 15.3 16 119 136 264 295 0.5 5 131 135.3 165 162 162 296 1 10 445 454 481 480 480 297 2 20 1039 1080 1135 1140 1009 298 p. aeruginosa 0 0 35.8 37.8 158 383 436 299 0.5 5 197 207 250 262 261 300 1 10 705 735 782 808 807 301 2 20 1011 1057 1121 1159 1146 302 S. aureus 0 0 46 45 148 184 406 303 0.5 5 215 163 173 183 184 304 1 10 643 494 326 309 276 305 2 20 1203 1032 595 525 281

EXAMPLE 306

In this experiment, six 25 mm sterile coverslips were placed into separate 100×15 mm sterile Petri dishes and two of each inoculated with 100 μl of one of three TSB broths: each broth containing one of E. coli, P. aeruginosa and S. aureus that had been allowed to incubate for 48-54 hours. In order to a fix the inoculum to the coverslips, the Petri dishes were placed on a low temperature hot plate for approximately 5 minutes. One of each of the inoculated Petri dishes was set aside as positive controls. The other was sprayed with 4 sprays of a 4:1 dilution of the bioactive compositions MI2. After 2-3 minutes the coverslips and liquid contents of each Petri dish was aseptically transferred into separate vials containing 20 ml of TSB and incubated at 37° C. for 24 hours. Negative controls were prepared by placing non-inoculated sterile coverslips into the 20 ml TSB and incubating as well. After 24 hours, no growth was observed with the negative controls or with those inoculated coverslips that had been sprayed with the bioactive composition of the present invention. Visual growth was observed in two of the positive controls (i.e., those vials containing the inoculated coverslips that had not been sprayed): the positive control for p. aeruginosa failed to show visual growth. It is believed that the failure of the later to show growth resulted from overheating the inoculum during the fixturing step.

EXAMPLE 307

In this experiment, two Trypticase soy agar (TSA) plates were inoculated with 500 μl of one of three TSB broths for a total of 6 inoculated plates: each broth contained one of E. coli, P. aeruginosa and S. aureus that had been allowed to incubate for 48-54 hours. The inoculum was evenly spread across the surface of the plate with a sterile loop. A 15 mm diameter disc of filter paper that had been dipped in a 4:1 dilution of the MI2 bioactive composition was placed in the center of one of each set of inoculated plates and all plates were placed in an incubator at 37° C. for 24 hours. Non-inoculated control plates were also placed in the incubator as well.

After 24 hours, visual growth was observed. No bacterial growth was seen in the non-inoculated plates. Growth was observed on all of the inoculated plates; however, in those plates wherein the treated filter paper had been placed, no growth was seen on or near the filter paper. Each treated filter paper disc manifested a clear zone of inhibition of bacterial growth.

EXAMPLE 308

In this experiment, two Trypticase soy agar (TSA) plates were innoculated with 500 μl of one of three TSB broths for a total of 6 inoculated plates: each broth contained one of E. coli, P. aeruginosa and S. aureus that had been allowed to incubate for 48-54 hours. The inoculum was evenly spread across the surface of the plate with a sterile loop. One of each inoculated plates was then sprayed, approximately 24 times, with the 4:1 dilution of the MI2 bioactive composition. The inoculated plates plus a set of plates non-inoculated control plates were placed in an incubator at 37° C. for 24 hours.

After 24 hours, visual growth was observed on inoculated, but untreated plates whereas no bacterial growth was seen in the non-inoculated plates or in those inoculated plates that had been sprayed with the diluted bioactive composition.

EXAMPLES 309 Bacterial MIC Study

A study was conducted to determine the minimum inhibitory concentration (MIC) of the MI2 acid solution, i.e., 200 ppm of each of silver, copper and zinc metal (see Examples 72-79). Three different bacteria were evaluated, Clavibacter michiganese, Pseudomonas syringae and Erwinia amylovora, each in a different growth medium appropriate for that bacteria, namely brain infusion agar/broth, nutrient agar/broth, and nutrient glucose agar/broth, respectively. In conducting the test, three sets of 10 test tubes were prepared, one set for each bacteria, and labeled 1 to 10. 0.5 ml of the appropriate broth was placed in each of test tubes 2 through 10. Then 0.5 ml of the MI2 solution was added to each of test tubes 1 and 2. 0.5 ml of the contents of test tube 2 was then transferred to test tube 3 and then 0.5 ml of test tube 3 to test tube 4 and so on to test tube 9. 0.5 ml or test tube 9 was discarded. A 0.5 ml suspension of each bacteria to be tested was then added to each of the ten tubes for that series and the tubes incubated for 24 hours at 26° C. Because the acid solution caused considerable cloudiness of the tubes to which it was added, macroscopic evaluation was not possible. Instead, each tube was subcultured onto corresponding agar plates. The observed growth was as indicated in Table 19 (a “+” indicates visual growth and a “−” no growth).

TABLE 19 Test Tube 1 2 3 4 5 6 7 8 9 10 Metals 200 50 25 12.5 6.75 3.125 1.56 0.782 0.391 0.195 concentration* (ppm) C. michiganese − − − − − − + + + + P. syringae − − − − − + + + + + E. amylovora − − − − − − + + + + *concentration of each metal, the total metal content is 3 time the number presented.

Based on the results presented in Table 19, the MIC of MI2 is 3.125 ppm for C. michiganese and for E. amylovora and 6.75 ppm for P. syringae. The bioefficacy of such low levels are anticipated to show synergy when combined with conventional fungicides/bactericides for these target organisms.

EXAMPLE 326 Mycobacterium Study

Three series of bacterial studies were conducted evaluate and compare the performance of the disinfectant solutions of the present invention to commercial disinfectants in killing Mycobacterium terrae (M. terrae ATCC 15755). M. terrae was chosen as it is a generally accepted surrogate or indicator for Mycobacterium tuberculosis, a mycobacteria that has been targeted for centuries, yet still persists owing, in part, to the appearance of drug-resistant strains in the 1980s and, more recently, the appearance of multidrug-resistant strains. Thus, any antibacterial agent that would be effective against M. tuberculosis or its related bacteria, especially without or with the lessening of resistance development, would be of tremendous benefit and value.

The disinfectant materials tested were the MI2 solution according to the present invention, SilverClene 24 from Agion Technologies of Wakefield, Mass., US, and Calvicide, a well known and widely available disinfectant. The test methodology was a slightly modified version of the methods employed in Taylor et. al. U.S. Pat. No. 6,616,922 and U.S. Pat. No. 6,107,261, both of which are incorporated herein in their entirety by reference. A 108 CFU/ml test suspension of M. terrae was prepared by suspending M. terrae in Butterfield's Buffer with 0.5% Tween 80 and vortexing well. 100 ml test samples of diluted (1:1 w/deionized water) and undiluted samples of each disinfectant were inoculated with 1.0 ml of the test suspension. A 100 ml deionized water control test sample was also inoculated. A 1.0 ml aliquot of each test sample was taken after certain specified time periods, as presented in Tables 20-22, diluted 1:1000 in deionized water and then subjected to a serial dilution and all dilutions plated on Middlebrook 7H10 agar with OADC enrichment and incubated at 37° C. with ˜10% CO₂ for 14-28 days and evaluated for growth.

The results of each series of tests are shown in Tables 20-22: Tables 20 and 21 presenting the results for the diluted disinfectants and Table 23 for the undiluted disinfectants. As seen, the solutions of the present invention proved to be an excellent bactericide for M. terrae with generally marked improvement in kill and kill rate as compared to conventional commercial products in both the diluted and undiluted state. Indeed, excellent results were shown with only 30 second exposure, with good results at just 10 seconds exposure, whereas the commercial products required 5 minutes or more exposure to show two log kill rates.

TABLE 20 Contact Control Calvicide Time % % % (sec) CFU/ml Reduction CFU/ml Reduction CFU/ml Reduction 120 1.21E5 — 8.8E4 27.27 4.1E5 n/r 300 1.33E5 n/r 7.1E4 46.62 3.2E4 75.94 600 1.31E5 n/r 6.4E4 51.15 4.2E3 96.79 900 1.36E5 n/r 4.9E4 63.97 2.3E3 99.83 1200 1.44E5 n/r 5.3E4 36.81 7.0E2 99.51 1500 1.46E5 n/r 2.9E4 80.14 1.3E3 99.11 1800 1.55E5 n/r 2.9E4 81.29 4.0E2 99.74

TABLE 21 Contact Control SilverClene 24 Time % % % (sec) CFU/ml Reduction CFU/ml Reduction CFU/ml Reduction 10 3.5E4 — 1.6E4 54.29 5.0E2 98.57 30 4.3E4 n/r 1.15E4 73.26 2.9E2 99.53 60 3.6E4 n/r 6.7E3 81.39 1.0E2 99.72 180 3.0E4 14.29  6.5E3 78.33 1.0E2 99.67 300 3.4E4 2.86 6.1E3 82.06 3.0E2 99.12 600 3.8E4 n/r 5.9E3 84.47 1.2E3 96.84 1800 3.3E4 5.71 2.2E3 93.33 1.0E2 99.7

TABLE 22 Contact Control Calvicide Time % % % (sec) CFU/ml Reduction CFU/ml Reduction CFU/ml Reduction 10 3.5E4 — 2.0E4 42.86 3.1E3 91.14 30 3.0E4 14.29 7.7E3 74.33 2.0E2 99.33 60 2.9E4 17.14 6.9E3 76.21 1.0E2 99.67 180 3.1E4 11.43 4.0E2 98.71 1.0E2 99.68 300 3.2E4 8.57 <100 99.69 <100 99.69 600 3.4E4 2.86 <100 99.71 <100 99.71 1800 3.0E4 14.29 <100 99.97 <100 99.97

Although the present invention has been described: with respect to the foregoing specific embodiments and examples, it should be appreciated that other embodiments utilizing the concept of the present invention are possible without departing from the scope of the invention. The present invention is defined by the claimed elements and any and all modifications, variations, or equivalents that fall within the spirit and scope of the underlying principles. 

1. A disinfectant solution comprising a) an acid solution having a pH of less than 6 whose acid concentration is from about 0.01% to about 10% and b) at least one antimicrobial metal ion source fully or partially dissolved in the acid solution; wherein the acid is present in a molar excess relative to the antimicrobial metal ions, the antimicrobial metal ions are selected from a combination of silver and copper ions, a combination of silver and zinc ions, a combination of copper and zinc ions and a combination of silver, copper and zinc ions and the total level of the antimicrobial metal ions in the solution is from about 20 ppm to about 1000 ppm.
 2. The disinfectant solution of claim 1 further comprising c) a surfactant system containing A) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, B) at least one anionic, non-ionic and/or amphoteric impact surfactant that impacts or interacts with cell wall membranes of microorganisms or (C) a combination of at least one of said wetting surfactant (A) and at least one impact surfactant (B).
 3. A disinfectant solution comprising a) an acid solution having a pH of less than 6 whose acid concentration is from about 0.01% to about 10%; b) at least one antimicrobial metal ion source fully or partially dissolved in the acid solution, and c) a surfactant system containing A) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, B) at least one anionic, non-ionic and/or amphoteric impact surfactant that impacts or interacts with cell wall membranes of microorganisms or (C) a combination of at least one of said wetting surfactant (A) and at least one impact surfactant (B), wherein the acid is present in at least a 2× molar excess relative to the antimicrobial metal ions and the total level of the antimicrobial metal ions in the solution is from about 20 ppm to about 1000 ppm.
 4. The composition of claim 3 wherein the antimicrobial metal ions are selected from the group consisting of silver ions, copper ions, zinc ions, a combination of silver and copper ions, a combination of silver and zinc ions, a combination of copper and zinc ions and a combination of silver, copper and zinc ions.
 5. The disinfectant solution of claim 3 wherein the concentration of antimicrobial metal ions is from about 25 to about 500 ppm.
 6. The disinfectant solution of claim 3 wherein the concentration of the antimicrobial metal ions is from about 50 to about 300 ppm.
 7. The disinfectant solution of claim 3 wherein the pH is from about 1.5 to about
 5. 8. The disinfectant solution of claim 3 wherein the pH is from about 2 to about
 4. 9. The disinfectant solution of claim 3 wherein the molar excess of acid relative to antimicrobial metal ions is at least 5 times molar excess.
 10. The disinfectant solution of claim 3 wherein the concentration of the acid is from about 0.1 to about 4 weight percent.
 11. The disinfectant solution of claim 3 wherein the surfactant is sodium lauroyl sarcosinate, sodium lauryl sulfate, lauryl dimethyl amine oxide, a combination of sodium lauroyl sarcosinate and sodium lauryl sulfate, a combination of sodium lauryl sulfate and lauryl dimethyl amine oxide, a combination of sodium lauroyl sarcosinate and lauryl dimethyl amine oxide, or a combination of sodium lauroyl sarcosinate, sodium lauryl sulfate and lauryl dimethyl amine oxide.
 12. The disinfectant solution of claim 3 wherein the surfactant acts as both an impact surfactant and a wetting surfactant.
 13. A method of disinfecting substrates said method comprising the steps of i) applying to said surface a disinfectant comprising a) an acid solution having a pH of less than 6 whose acid concentration is from about 0.01% to about 10%; b) at least one antimicrobial metal ion source fully or partially dissolved in the acid solution, and c) a surfactant system containing A) at least one wetting surfactant known for enhancing the wetting or wet out of substrate surfaces with aqueous solutions, B) at least one anionic, non-ionic and/or amphoteric impact surfactant that impacts or interacts with cell wall membranes of microorganisms or (C) a combination of at least one of said wetting surfactant (A) and at least one impact surfactant (B), wherein the acid is present in at least a 2× molar excess relative to the antimicrobial metal ions and the total level of the antimicrobial metal ions in the solution is from about 20 ppm to about 1000 ppm. and ii) either allowing the solvent of the solution to evaporate so as to leave an antimicrobial presence on the substrate or, after a short period of time, wiping the excess solution from the surface.
 14. The composition of claim 13 wherein the antimicrobial metal ions are selected from the group consisting of silver ions, copper ions, zinc ions, a combination of silver and copper ions, a combination of silver and zinc ions, a combination of copper and zinc ions and a combination of silver, copper and zinc ions.
 15. The disinfectant solution of claim 13 wherein the concentration of antimicrobial metal ions is from about 25 to about 500 ppm.
 16. The disinfectant solution of claim 13 wherein the concentration of the antimicrobial metal ions is from about 50 to about 300 ppm.
 17. The disinfectant solution of claim 13 wherein the pH is from about 1.5 to about
 5. 18. The disinfectant solution of claim 13 wherein the molar excess of acid relative to antimicrobial metal ions is at least 5 times molar excess.
 19. The disinfectant solution of claim 13 wherein the concentration of the acid is from about 0.1 to about 4 weight percent.
 20. The disinfectant solution of claim 13 wherein the surfactant is sodium lauroyl sarcosinate, sodium lauryl sulfate, lauryl dimethyl amine oxide, a combination of sodium lauroyl sarcosinate and sodium lauryl sulfate, a combination of sodium lauryl sulfate and lauryl dimethyl amine oxide, a combination of sodium lauroyl sarcosinate and lauryl dimethyl amine oxide, or a combination of sodium lauroyl sarcosinate, sodium lauryl sulfate and lauryl dimethyl amine oxide.
 21. The method of claim 13 wherein the targeted microorganism of the disinfectant is M. tuberculosis. 